ℹ️ Skipped - page is already crawled
| Filter | Status | Condition | Details |
|---|---|---|---|
| HTTP status | PASS | download_http_code = 200 | HTTP 200 |
| Age cutoff | PASS | download_stamp > now() - 6 MONTH | 0.2 months ago (distributed domain, exempt) |
| History drop | PASS | isNull(history_drop_reason) | No drop reason |
| Spam/ban | PASS | fh_dont_index != 1 AND ml_spam_score = 0 | ml_spam_score=0 |
| Canonical | PASS | meta_canonical IS NULL OR = '' OR = src_unparsed | Not set |
| Property | Value |
|---|---|
| URL | https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles |
| Last Crawled | 2026-04-09 19:32:44 (6 days ago) |
| First Indexed | 2013-10-07 18:10:03 (12 years ago) |
| HTTP Status Code | 200 |
| Meta Title | Fuel economy in automobiles - Wikipedia |
| Meta Description | null |
| Meta Canonical | null |
| Boilerpipe Text | New light-duty vehicle fuel economy by vehicle type from vehicle manufacturers in the United States, in miles per gallon (1975 - 2019)
Fuel consumption monitor from a 2006
Honda Airwave
. The displayed fuel economy is 18.1 km/L (5.5 L/100 km; 43 mpg
‑US
).
A
Briggs and Stratton Flyer
from 1916. Originally an experiment in creating a fuel-saving automobile in the United States, the vehicle weighed only 135 lb (61.2 kg) and was an adaptation of a small gasoline engine originally designed to power a bicycle.
[
1
]
The
fuel economy
or
fuel efficiency
of an
automobile
relates to the
distance traveled
by a vehicle and the amount of
fuel
consumed. It can be expressed in terms of the volume of fuel to travel a given distance, such as in
litres per 100 kilometres
(L/100
km), or through its inverse, the distance traveled per unit volume of fuel consumed, as in
kilometres per litre
(km/L) or
miles per gallon
(mpg). Since fuel economy of vehicles is a significant factor in
air pollution
, the importation of
motor fuel
can be a large part of a nation's
foreign trade
and consumers frequently undervalue fuel efficiency, many countries impose requirements for fuel economy.
Different methods are used to approximate the actual performance of the vehicle. The energy in fuel is required to overcome various losses (
wind resistance
,
tire drag
, and others) encountered while propelling the vehicle, and in providing power to vehicle systems such as ignition or air conditioning. Various strategies can be employed to reduce losses at each of the conversions between the
chemical energy
in the fuel and the
kinetic energy
of the vehicle. Driver behavior can affect fuel economy; maneuvers such as sudden acceleration and heavy
braking
waste energy.
Electric cars
use
kilowatt-hours
of electricity per 100 kilometres (kWh/100km); in the U.S., an equivalence measure, such as
miles per gallon gasoline equivalent
(US gallon) has been created to attempt to compare them.
Quantities and units of measure
[
edit
]
Conversion from mpg to L/100 km: blue - US
gallon
; red - UK gallon (imperial)
The fuel efficiency of motor vehicles can be expressed in multiple ways:
Fuel consumption
is the fuel used per unit distance; for example,
litres
per 100
kilometres
(L/100 km)
. The
lower
the value, the more economic a vehicle is; this is the measure generally used across
Europe
(except the UK, Denmark and The Netherlands - see below),
Africa
,
New Zealand
,
Australia
, and
Canada
,
Uruguay
,
Paraguay
,
Guatemala
,
Colombia
,
China
, and
Madagascar
, and in the former
CIS
states.
[
citation needed
]
,
Fuel economy
is the distance travelled per unit volume of fuel used; for example,
kilometres per litre (km/L)
or
miles
per
gallon
(MPG)
. The
higher
the value, the more economic a vehicle is (the more distance it can travel with a certain volume of fuel). This measure is popular in the US and the UK (mpg), but in Europe, India, Japan, South Korea the metric unit
km/L
is used instead.
The formula for converting to miles per US gallon (3.7854 L) from L/100 km is
, where
is value of L/100 km. For miles per Imperial gallon (4.5461 L) the formula is
.
Europe now uses the
WLTP
standard to compare the fuel economy of all new vehicles.
Fuel economy can be expressed in two ways:
Units of fuel per fixed distance
Generally expressed in liters per 100 kilometers (L/100 km), used in most European countries, Canada, China, South Africa, Australia and New Zealand. Irish law allows for the use of miles per imperial
gallon
, alongside liters per 100 kilometers.
[
2
]
Liters per 100 kilometers may be used alongside miles per imperial
gallon
in the UK. The
window sticker
on new US cars displays the vehicle's fuel consumption in US gallons per 100 miles, in addition to the traditional mpg number.
[
3
]
A lower number means more efficient, while a higher number means less efficient.
Units of distance per fixed fuel unit
Miles per
gallon
(mpg) are commonly used in the United States, the United Kingdom, and Canada (alongside L/100 km). Kilometers per liter (km/L) are more commonly used elsewhere in the Americas, Asia, parts of Africa and Oceania. In the
Levant
km/20 L is used, known as kilometers per
tanaka
, a
metal container
which has a volume of twenty liters.
[
citation needed
]
When mpg is used, it is necessary to identify the type of gallon: the imperial gallon is 4.54609 liters, and the U.S. gallon is 3.785 liters. When using a measure expressed as distance per fuel unit, a higher number means more efficient, while a lower number means less efficient.
Conversions of units:
Trucks' share of US vehicles produced, has tripled since 1975. Though vehicle fuel efficiency has increased within each category, the overall trend toward less efficient types of vehicles has offset some of the benefits of greater fuel economy and reduction of carbon dioxide emissions.
[
4
]
Without the shift towards SUVs, energy use per unit distance could have fallen 30% more than it did from 2010 to 2022.
[
5
]
While the
thermal efficiency
(mechanical output to chemical energy in fuel) of petroleum
engines
has increased since the beginning of the
automotive era
, this is not the only factor in fuel economy. The design of automobile as a whole and usage pattern affects the fuel economy. Published fuel economy is subject to variation between jurisdiction due to variations in testing protocols.
One of the first studies to determine fuel economy in the United States was the
Mobil Economy Run
, which was an event that took place every year from 1936 (except during
World War II
) to 1968. It was designed to provide real, efficient
fuel efficiency
numbers during a coast-to-coast test on real roads and with regular traffic and weather conditions. The
Mobil
Oil Corporation sponsored it and the
United States Auto Club
(USAC) sanctioned and operated the run. In more recent studies, the average fuel economy for new passenger car in the United States improved from 17 mpg (13.8 L/100 km) in 1978 to 22 mpg (10.7 L/100 km) in 1982.
[
6
]
The average
[
a
]
fuel economy for new 2020 model year cars, light trucks and SUVs in the United States was 25.4 miles per US gallon (9.3 L/100 km).
[
7
]
2019 model year cars (ex. EVs) classified as "midsize" by the US EPA ranged from 12 to 56 mpg
US
(20 to 4.2 L/100 km)
[
8
]
However, due to environmental concerns caused by CO
2
emissions, new EU regulations are being introduced to reduce the average emissions of cars sold beginning in 2012, to 130 g/km of CO
2
, equivalent to 4.5 L/100 km (52 mpg
US
, 63 mpg
imp
) for a diesel-fueled car, and 5.0 L/100 km (47 mpg
US
, 56 mpg
imp
) for a gasoline (petrol)-fueled car.
[
9
]
The average consumption across the fleet is not immediately affected by the
new vehicle
fuel economy: for example, Australia's car fleet average in 2004 was 11.5 L/100 km (20.5 mpg
US
),
[
10
]
compared with the average new car consumption in the same year of 9.3 L/100 km (25.3 mpg
US
)
[
11
]
Speed and fuel economy studies
[
edit
]
1997 fuel economy statistics for various US models
Fuel economy at steady speeds with selected vehicles was studied in 2010. The most recent study
[
12
]
indicates greater fuel efficiency at higher speeds than earlier studies; for example, some vehicles achieve better fuel economy at 100 km/h (62 mph) rather than at 70 km/h (43 mph),
[
12
]
although not their best economy, such as the 1994
Oldsmobile Cutlass Ciera
with the
LN2
2.2L engine, which has its best economy at 90 km/h (56 mph) (8.1 L/100 km (29 mpg
‑US
)), and gets better economy at 105 km/h (65 mph) than at 72 km/h (45 mph) (9.4 L/100 km (25 mpg
‑US
) vs 22 mpg
‑US
(11 L/100 km)). The proportion of driving on
high speed roadways
varies from 4% in Ireland to 41% in the Netherlands.
When the US
National Maximum Speed Law
's 55 mph (89 km/h) speed limit was mandated from 1974 to 1995, there were complaints that fuel economy could decrease instead of increase. The 1997 Toyota Celica got better fuel-efficiency at 105 km/h (65 mph) than it did at 65 km/h (40 mph) (5.41 L/100 km (43.5 mpg
‑US
) vs 5.53 L/100 km (42.5 mpg
‑US
)), although even better at 60 mph (97 km/h) than at 65 mph (105 km/h) (48.4 mpg
‑US
(4.86 L/100 km) vs 43.5 mpg
‑US
(5.41 L/100 km)), and its best economy (52.6 mpg
‑US
(4.47 L/100 km)) at only 25 mph (40 km/h). Other vehicles tested had from 1.4 to 20.2% better fuel-efficiency at 90 km/h (56 mph) vs. 105 km/h (65 mph). Their best economy was reached at speeds of 40 to 90 km/h (25 to 56 mph) (see graph).
[
12
]
Officials hoped that the 55 mph (89 km/h) limit, combined with a ban on ornamental lighting, no gasoline sales on Sunday, and a 15% cut in gasoline production, would reduce total gasoline consumption by 200,000
barrels
a day, representing a 2.2% drop from annualized 1973 gasoline consumption levels.
[
13
]
[
b
]
This was partly based on a belief that cars achieve maximum efficiency between 40 and 50 mph (65 and 80 km/h) and that trucks and buses were most efficient at 55 mph (89 km/h).
[
15
]
In 1998, the U.S.
Transportation Research Board
footnoted an estimate that the 1974 National Maximum Speed Limit (NMSL) reduced fuel consumption by 0.2 to 1.0 percent.
[
16
]
Rural interstates, the roads most visibly affected by the NMSL, accounted for 9.5% of the U.S' vehicle-miles-traveled in 1973,
[
17
]
but such free-flowing roads typically provide more fuel-efficient travel than conventional roads.
[
18
]
[
19
]
[
20
]
Discussion of statistics
[
edit
]
A reasonably modern European
supermini
and many mid-size cars, including station wagons, may manage
motorway
travel at 5 L/100 km (47 mpg
‑US
; 56 mpg
‑imp
) or 6.5 L/100 km (36 mpg
‑US
; 43 mpg
‑imp
), with
carbon dioxide
emissions of around 140 g/km.
An average
North American
mid-size car
averages 21 mpg
‑US
(11 L/100 km; 25 mpg
‑imp
)) city, 27 mpg
‑US
(8.7 L/100 km; 32 mpg
‑imp
)) highway; a
full-size
SUV
usually averages 13 mpg
‑US
(18 L/100 km; 16 mpg
‑imp
) city and 16 mpg
‑US
(15 L/100 km; 19 mpg
‑imp
) highway.
Pickup trucks
vary considerably; whereas a 4 cylinder-engined light pickup can achieve 28 mpg
‑US
(8.4 L/100 km; 34 mpg
‑imp
), a
V8
full-size pickup with extended cabin averages13 mpg
‑US
(18 L/100 km; 16 mpg
‑imp
) city and 15 mpg
‑US
(16 L/100 km; 18 mpg
‑imp
) highway.
The average fuel economy for all vehicles on the road is higher in Europe than the United States because the higher cost of fuel changes
consumer behaviour
. In the UK, an imperial gallon of fuel cost US$6.06 in 2005. The average cost in the United States was US$2.61 for a US gallon.
[
21
]
European-built cars are generally more fuel-efficient than US vehicles. While Europe has many highly efficiency diesel cars, European gasoline/petrol vehicles are on average also more efficient than gasoline-powered vehicles in the USA. Most European vehicles cited in the CSI study run on diesel engines, which tend to achieve greater fuel efficiency than gasoline/petrol engines. Selling those cars in the United States is difficult because of emission standards, notes Walter McManus, a fuel economy expert at the University of Michigan Transportation Research Institute. "For the most part, European diesels don’t meet U.S. emission standards", McManus said in 2007. Another reason why many European models are not sold in the United States is that labor unions object to having the big 3 import any new foreign built models regardless of fuel economy while laying off workers at home.
[
22
]
An example of European cars' capabilities of fuel economy is the
microcar
Smart Fortwo
cdi, which can achieve up to 3.4 L/100 km (83 mpg
‑imp
; 69 mpg
‑US
) using a
turbocharged
three-cylinder
30 kW (40 hp) Diesel engine. The Fortwo is produced by
Daimler AG
and is only sold by one company in the United States. Furthermore, the world record in fuel economy of production cars is held by the
Volkswagen Group
, with special production models (labeled "3L") of the
Volkswagen Lupo
and the
Audi A2
, consuming as little as 3 L/100 km (94 mpg
‑imp
; 78 mpg
‑US
).
[
23
]
[
clarification needed
]
Diesel engines
generally achieve greater fuel efficiency than petrol (gasoline) engines. Passenger car diesel engines have
energy efficiency
of up to 41% but more typically 30%, and petrol engines of up to 37.3%, but more typically 20%. A common margin is 25% more efficiency for a turbodiesel.
For example, the current model Skoda Octavia, using Volkswagen engines, has a combined European fuel efficiency of 5.7 L/100 km (50 mpg
‑imp
; 41 mpg
‑US
) for the 78 kW (105 hp) petrol engine and 4.5 L/100 km (63 mpg
‑imp
; 52 mpg
‑US
) for the 78 kW (105 hp) heavier diesel engine vehicle. The higher compression ratio raises the energy efficiency, but diesel fuel also contains approximately 10% more energy per unit volume than gasoline/petrol which contributes to the reduced fuel consumption for a given power output.
In 2002, the United States had 85,174,776 trucks, and averaged 13.5 mpg
‑US
(17.4 L/100 km; 16.2 mpg
‑imp
). Large trucks, over 33,000 lb (15,000 kg), averaged 5.7 mpg
‑US
(41 L/100 km; 6.8 mpg
‑imp
).
[
24
]
U.S. Truck fuel economy
GVWR
lbs
Number
Percentage
Average miles per truck
fuel economy
Percentage of fuel use
6,000 lbs and less
51,941,389
61.00%
11,882
17.6
42.70%
6,001 – 10,000 lbs
28,041,234
32.90%
12,684
14.3
30.50%
Light truck subtotal
79,982,623
93.90%
12,163
16.2
73.20%
10,001 – 14,000 lbs
691,342
0.80%
14,094
10.5
1.10%
14,001 – 16,000 lbs
290,980
0.30%
15,441
8.5
0.50%
16,001 – 19,500 lbs
166,472
0.20%
11,645
7.9
0.30%
19,501 – 26,000 lbs
1,709,574
2.00%
12,671
7
3.20%
Medium truck subtotal
2,858,368
3.40%
13,237
8
5.20%
26,001 – 33,000 lbs
179,790
0.20%
30,708
6.4
0.90%
33,001 lbs and up
2,153,996
2.50%
45,739
5.7
20.70%
Heavy truck subtotal
2,333,786
2.70%
44,581
5.8
21.60%
Total
85,174,776
100.00%
13,088
13.5
100.00%
The average economy of automobiles in the United States in 2002 was 22.0 miles per US gallon (10.7 L/100 km; 26.4 mpg
‑imp
). By 2010 this had increased to 23.0 miles per US gallon (10.2 L/100 km; 27.6 mpg
‑imp
). Average fuel economy in the United States gradually declined until 1973, when it reached a low of 13.4 miles per US gallon (17.6 L/100 km; 16.1 mpg
‑imp
) and gradually has increased since, as a result of higher fuel cost.
[
25
]
A study indicates that a 10% increase in gas prices will eventually produce a 2.04% increase in fuel economy.
[
26
]
One method by car makers to increase fuel efficiency is
lightweighting
in which lighter-weight materials are substituted in for improved engine performance and handling.
[
27
]
Differences in testing standards
[
edit
]
Identical vehicles can have varying fuel consumption figures listed depending upon the testing methods of the jurisdiction.
[
28
]
Lexus
IS 250
– petrol 2.5 L
4GR-FSE
V6
, 204 hp (153 kW), 6 speed automatic, rear wheel drive
Australia
(L/100 km) – 'combined' 9.1, 'urban' 12.7, 'extra-urban' 7.0
[
18
]
Canada
(L/100 km) – 'combined' 9.6, 'city' 11.1, 'highway' 7.8
[
29
]
European Union
(L/100 km) – 'combined' 8.9, 'urban' 12.5, 'extra-urban' 6.9
[
19
]
United States
(L/100 km) – 'combined' 9.8, 'city' 11.2, 'highway' 8.1
[
20
]
Energy considerations
[
edit
]
Since the total force opposing the vehicle's motion (at constant speed) multiplied by the distance through which the vehicle travels represents the work that the vehicle's engine must perform, the study of fuel economy (the amount of energy consumed per unit of distance traveled) requires a detailed analysis of the forces that oppose a vehicle's motion. In terms of physics, Force = rate at which the amount of work generated (energy delivered) varies with the distance traveled, or:
Note: The amount of work generated by the vehicle's power source (energy delivered by the engine) would be exactly proportional to the amount of fuel energy consumed by the engine if the engine's efficiency is the same regardless of power output, but this is not necessarily the case due to the operating characteristics of the internal combustion engine.
For a vehicle whose source of power is a heat engine (an engine that uses heat to perform useful work), the amount of fuel energy that a vehicle consumes per unit of distance (level road) depends upon:
The
thermodynamic efficiency of the heat engine
;
Frictional losses within the
drivetrain
;
Rolling resistance
within the wheels and between the road and the wheels;
Non-motive subsystems powered by the engine, such as
air conditioning
,
engine cooling
, and the
alternator
;
Aerodynamic drag
from moving through air;
Energy converted by
frictional brakes
into waste heat, or losses from
regenerative braking
in
hybrid vehicles
;
Fuel consumed while the engine is not providing power but still running, such as while
idling
, minus the subsystem loads.
[
30
]
Energy dissipation in city and highway driving for a mid-size gasoline-powered car
Ideally, a car traveling at a constant velocity on level ground in a vacuum with frictionless wheels could travel at any speed without consuming any energy beyond what is needed to get the car up to speed. Less ideally, any vehicle must expend energy on overcoming road load forces, which consist of aerodynamic drag, tire rolling resistance, and inertial energy that is lost when the vehicle is decelerated by friction brakes. With ideal
regenerative braking
, the inertial energy could be completely recovered, the only options for reducing aerodynamic drag or rolling resistance other than optimizing the vehicle's shape and the tire design. Road load energy or the energy demanded at the wheels, can be calculated by evaluating the vehicle equation of motion over a specific driving cycle.
[
31
]
The vehicle powertrain must then provide this minimum energy to move the vehicle and will lose a large amount of additional energy in the process of converting fuel energy into work and transmitting it to the wheels. Overall, the sources of energy loss in moving a vehicle may be summarized as follows:
Engine efficiency
(20–30%), which varies with engine type, the mass of the automobile and its load, and engine speed (usually measured in
RPM
).
Aerodynamic drag
force, which increases roughly by the
square of the car's speed
, but notes that
drag power goes by the cube of the car's speed
.
Rolling friction
.
Braking, although
regenerative braking
captures some of the energy that would otherwise be lost.
Losses in the
transmission
.
Manual transmissions
can be up to 94% efficient whereas older
automatic transmissions
may be as low as 70% efficient
[
32
]
Automated manual transmissions
, which have the same mechanical internals as conventional
manual transmissions
, will give the same efficiency as a pure manual gearbox plus the added bonus of intelligence selecting optimal shifting points, and/or automated clutch control but manual shifting, as with older
semi-automatic transmissions
.
Air conditioning. The power required for the engine to turn the compressor decreases the fuel-efficiency, though only when in use. This may be offset by the reduced drag of the vehicle compared with driving with the windows down. The efficiency of AC systems gradually deteriorates due to dirty filters etc.; regular maintenance prevents this. The extra mass of the air conditioning system will cause a slight increase in fuel consumption.
Power steering. The older hydraulic power steering systems are powered by a hydraulic pump constantly engaged to the engine. Power assistance required for steering is inversely proportional to the vehicle speed so the constant load on the engine from a hydraulic pump reduces fuel efficiency. More modern designs improve fuel efficiency by only activating the power assistance when needed; this is done by using either direct electrical power steering assistance or an electrically powered hydraulic pump.
Cooling. The older cooling systems used a constantly engaged mechanical fan to draw air through the radiator at a rate directly related to the engine speed. This constant load reduces efficiency. More modern systems use electrical fans to draw additional air through the radiator when extra cooling is required.
Electrical systems. Headlights, battery charging, active suspension, circulating fans, defrosters, media systems, speakers, and other electronics can also significantly increase fuel consumption, as the energy to power these devices causes an increased load on the alternator. Since alternators are commonly only 40–60% efficient, the added load from electronics on the engine can be as high as 3 horsepower (2.2 kW) at any speed including idle. In the FTP 75 cycle test, a 200-watt load on the alternator reduces fuel efficiency by 1.7 mpg
‑US
(140 L/100 km; 2.0 mpg
‑imp
).
[
33
]
Headlights, for example, consume 110 watts on low and up to 240 watts on high. These electrical loads can cause much of the discrepancy between real-world and EPA tests, which only include the electrical loads required to run the engine and basic climate control.
Standby. The energy is needed to keep the engine running while it is not providing power to the wheels, i.e., when stopped, coasting or braking.
Fuel-efficiency decreases from electrical loads are most pronounced at lower speeds because most electrical loads are constant while engine load increases with speed. So at a lower speed, a higher proportion of
engine power
is used by electrical loads. Hybrid cars see the greatest effect on fuel-efficiency from electrical loads because of this proportional effect.
Fuel economy-boosting technologies
[
edit
]
Engine-specific technology
[
edit
]
Type
Technology
Explanation
Inventor
Notes
Engine cycle
Replacing petrol engines with diesel engines
Reduces brake specific fuel consumption at lower RPM
Herbert Akroyd Stuart
Engine combustion strategies
Electronic control of the cooling system
Optimizes engine running temperature
Stratified Charge combustion
Injects fuel into cylinder just before ignition, increasing compression ratio
For use in petrol engines
Lean burn combustion
Increases air/fuel ratio to reduce throttling losses
Chrysler
https://www.youtube.com/watch?v=KnNX6gtDyhg
Cooled
exhaust gas recirculation
(petrol)
Reduces throttling losses, heat rejection, chemical dissociation, and specific heat ratio
Cooled exhaust gas recirculation (diesel)
Lowers peak combustion temperatures
Atkinson cycle
Lengthens power stroke to achieve greater thermal efficiency
James Atkinson
Atkinson cycle
Variable valve timing
and
variable valve lift
Alters valve lift timing and height for precise control over intake and exhaust
William Howe and William Williams (
Robert Stephenson and Company
) invented the first
variable timing valve
Variable geometry turbocharging
Optimizes airflow with adjustable vanes to regulate turbocharger's air intake and eliminate turbo lag
Garrett (
Honeywell
)
VNT Vanes Open
Twincharging
Combines a supercharger with a turbocharger to eliminate turbo lag
Lancia
For use in small-displacement engines
Gasoline direct injection (GDI) engines
Allows for stratified fuel charge and ultra-lean burn
Leon Levavasseur
Turbocharged Direct Injection
diesel engines
Combines direct injection with a turbocharger
Volkswagen
Common rail direct injection
Increases injection pressure
Robert Huber
Piezoelectric diesel injectors
Uses multiple injections per engine cycle for increased precision
Cylinder management
Shuts off individual cylinders when their power output is not needed
HCCI (Homogeneous Charge Compression Ignition) combustion
Allows leaner and higher compression burn
https://www.youtube.com/watch?v=B8CnYljXAS0
Scuderi engine
Eliminates recompression losses
Carmelo J. Scuderi
Scuderi engine
Compound engines (6-stroke engine or turbo-compound engine)
Recovers exhaust energy
Two-stroke diesel engines
Increases power to weight ratio
Charles F. Kettering
High-efficiency gas turbine engines
Increases power to weight ratio
Turbosteamer
Uses heat from the engine to spin a mini turbine to generate power
Raymond Freymann (BMW)
Stirling hybrid battery vehicle
Increases thermal efficiency
Still largely theoretical, although prototypes have been produced by Dean Kamen
Time-optimized piston path
Captures energy from gases in the cylinders at their highest temperatures
Engine internal losses
Downsized engines with a supercharger or a turbocharger
Reduces engine displacement while maintaining sufficient torque
Saab, starting with the 99 in 1978.
2014-Global-Turbo-Forecast
Lower-friction lubricants (engine oil, transmission fluid, axle fluid)
Reduces energy lost to friction
Lower viscosity engine oils
Reduces hydrodynamic friction and energy required to circulate
Variable displacement oil pump
Avoids excessive flow rate at high engine speed
Electrifying engine accessories (water pump, power steering pump, and air conditioner compressor)
Sends more engine power to the transmission or reduces the fuel required for the same traction power
Roller type cam, low friction coating on piston skirt and optimizing load-bearing surface, e.g. camshaft bearing and connective rods.
Reduces engine frictions
Engine running conditions
Coolant additives
Increases the thermal efficiency of the cooling system
Increasing the number of gearbox ratios in manual gearboxes
Lowers the engine rpm at cruise
Reducing the volume of water-based cooling systems
Engine reaches its efficient operating temperature more quickly
Start-stop system
Automatically shuts off engine when vehicle is stopped, reducing idle time
Downsized engines with an electric drive system and battery
Avoids low-efficiency idle and power conditions
Other vehicle technologies
[
edit
]
Type
Technology
Explanation
Inventor
Notes
Transmission losses
Continuously variable transmission (CVT)
Enables engine to run at its most efficient RPM
For use in automatic gearboxes
Locking torque converters in automatic transmissions
Reduces slip and power losses in the converter
Rolling resistance
Lighter construction materials (aluminum, fiberglass, plastic, high-strength steel, and carbon fiber)
Reduces vehicle weight
Increasing tire pressure
Lowers tire deformation under weight
Replacing tires with low rolling resistance (LRR) models
Lowers rolling resistance
[
34
]
Series parallel hybrid
Using an electric motor for the base power and an IC engine for assists and boosts, when needed
Decreases fuel consumption by running the petrol engine only when needed, in this way also environmentally friendly.
TRW
Energy saving
Lighter materials for moving parts (pistons, crankshaft, gears, and alloy wheels)
Reduces the energy required to move parts
Regenerative braking
Captures kinetic energy while braking
Louis Antoine Kriéger
For use in hybrid or electric vehicles
Recapturing waste heat from the exhaust system
Converts heat energy into electricity using
thermoelectric cooling
Jean Charles Athanase Peltier
Regenerative shock absorbers
Recaptures wasted energy in the vehicle suspension
[
35
]
Levant Power
Traffic management
Active highway management
Matches speed limits and vehicles allowed to join motorways with traffic density to maintain traffic throughput
Vehicle electronic control systems that automatically maintain distances between vehicles on motorways
Reduces ripple back braking and consequent re-acceleration
Future technologies
[
edit
]
Technologies that may improve fuel efficiency, but are not yet on the market, include:
HCCI
(Homogeneous Charge Compression Ignition) combustion
Scuderi engine
Compound engines
Two-stroke diesel engines
High-efficiency
gas turbine engines
BMW's
Turbosteamer
– using the heat from the engine to spin a mini turbine to generate power
Vehicle electronic control systems that automatically maintain distances between vehicles on motorways/freeways that reduce
ripple back braking
, and consequent re-acceleration.
Time-optimized piston path, to capture energy from hot gases in the cylinders when they are at their highest temperatures
[
citation needed
]
sterling hybrid battery vehicle
Many
aftermarket consumer products
exist that are purported to increase fuel economy; many of these claims have been discredited. In the United States, the Environmental Protection Agency maintains a list of devices that have been tested by independent laboratories and makes the test results available to the public.
[
36
]
Fuel economy maximizing behaviors
[
edit
]
Governments, various environmentalist organizations, and companies like
Toyota
and
Shell Oil Company
have historically urged drivers to maintain adequate air pressure in
tires
and careful acceleration/deceleration habits. Keeping track of fuel efficiency stimulates fuel economy-maximizing behavior.
[
37
]
A five-year partnership between
Michelin
and
Anglian Water
shows that 60,000 liters of fuel can be saved on tire pressure. The Anglian Water fleet of 4,000 vans and cars are now lasting their full lifetime. This shows the impact that tire pressures have on the fuel efficiency.
[
38
]
Fuel economy as part of quality management regimes
[
edit
]
Environmental management
systems
EMAS
, as well as good fleet management, includes record-keeping of the fleet fuel consumption. Quality management uses those figures to steer the measures acting on the fleets. This is a way to check whether procurement, driving, and maintenance in total have contributed to changes in the fleet's overall consumption.
Fuel economy standards and testing procedures
[
edit
]
Gasoline new passenger car fuel efficiency
Country
2004 average
Requirement
2004
2005
2008
Later
People's Republic of China
[
39
]
6.9 L/100 km
6.9 L/100 km
6.1 L/100 km
United States
24.6 mpg (9.5 L/100 km) (cars and trucks)*
27 mpg (8.7 L/100 km) (cars only)*
35 mpg (6.7 L/100 km) (Model Year 2020, cars & light trucks)
European Union
4.1 L/100 km (2020,
NEDC
)
Japan
[
11
]
6.7 L/100 km
CAFE
eq (2010)
Australia
[
11
]
8.08 L/100 km CAFE eq (2002)
none
none (as of March 2019)
[
40
]
* highway ** combined
From October 2008, all new cars had to be sold with a sticker on the windscreen showing the fuel consumption and the CO
2
emissions.
[
41
]
Fuel consumption figures are expressed as
urban
,
extra urban
and
combined
, measured according to
ECE Regulations
83 and 101 – which are the based on the
European driving cycle
; previously, only the
combined
number was given.
Australia also uses a star rating system, from one to five stars, that combines greenhouse gases with pollution, rating each from 0 to 10 with ten being best. To get 5 stars a combined score of 16 or better is needed, so a car with a 10 for economy (greenhouse) and a 6 for emission or 6 for economy and 10 for emission, or anything in between would get the highest 5 star rating.
[
42
]
The lowest rated car is the
Ssangyong Korrando
with automatic transmission, with one star, while the highest rated was the Toyota Prius hybrid. The Fiat 500, Fiat Punto and Fiat Ritmo as well as the Citroen C3 also received 5 stars.
[
43
]
The greenhouse rating depends on the fuel economy and the type of fuel used. A greenhouse rating of 10 requires 60 or less grams of CO
2
per km, while a rating of zero is more than 440 g/km CO
2
. The highest greenhouse rating of any 2009 car listed is the Toyota Prius, with 106 g/km CO
2
and 4.4 L/100 km (64 mpg
‑imp
; 53 mpg
‑US
). Several other cars also received the same rating of 8.5 for greenhouse. The lowest rated was the Ferrari 575 at 499 g/km CO
2
and 21.8 L/100 km (13.0 mpg
‑imp
; 10.8 mpg
‑US
). The Bentley also received a zero rating, at 465 g/km CO
2
. The best fuel economy of any year is the 2004–2005
Honda Insight
, at 3.4 L/100 km (83 mpg
‑imp
; 69 mpg
‑US
).
Vehicle manufacturers follow a controlled laboratory testing procedure to generate the fuel consumption data that they submit to the Government of Canada. This controlled method of fuel consumption testing, including the use of standardized fuels, test cycles and calculations, is used instead of on-road driving to ensure that all vehicles are tested under identical conditions and that the results are consistent and repeatable.
Selected test vehicles are "run in" for about 6,000 km before testing. The vehicle is then mounted on a chassis dynamometer programmed to take into account the aerodynamic efficiency, weight and rolling resistance of the vehicle. A trained driver runs the vehicle through standardized driving cycles that simulate trips in the city and on the highway. Fuel consumption ratings are derived from the emissions generated during the driving cycles.
[
44
]
THE 5 CYCLE TEST:
The
city test
simulates urban driving in stop-and-go traffic with an average speed of 34 km/h and a top speed of 90 km/h. The test runs for approximately 31 minutes and includes 23 stops. The test begins from a cold engine start, which is similar to starting a vehicle after it has been parked overnight during the summer. The final phase of the test repeats the first eight minutes of the cycle but with a hot engine start. This simulates restarting a vehicle after it has been warmed up, driven and then stopped for a short time. Over five minutes of test time are spent idling, to represent waiting at traffic lights. The ambient temperature of the test cell starts at 20 °C and ends at 30 °C.
The
highway test
simulates a mixture of open highway and rural road driving, with an average speed of 78 km/h and a top speed of 97 km/h. The test runs for approximately 13 minutes and does not include any stops. The test begins from a hot engine start. The ambient temperature of the test cell starts at 20 °C and ends at 30 °C.
In the
cold temperature operation test
, the same driving cycle is used as in the standard
city test
, except that the ambient temperature of the test cell is set to −7 °C.
In the
air conditioning test
, the ambient temperature of the test cell is raised to 35 °C. The vehicle's climate control system is then used to lower the internal cabin temperature. Starting with a warm engine, the test averages 35 km/h and reaches a maximum speed of 88 km/h. Five stops are included, with idling occurring 19% of the time.
The
high speed/quick acceleration test
averages 78 km/h and reaches a top speed of 129 km/h. Four stops are included and brisk acceleration maximizes at a rate of 13.6 km/h per second. The engine begins warm and air conditioning is not used. The ambient temperature of the test cell is constantly 25 °C.
Tests 1, 3, 4, and 5 are averaged to create the city driving fuel consumption rate.
Tests 2, 4, and 5 are averaged to create the highway driving fuel consumption rate.
[
44
]
Irish fuel economy label
In the European Union, passenger vehicles are commonly tested using two drive cycles, and corresponding fuel economies are reported as "urban" and "extra-urban", in liters per 100 km and (in the UK) in miles per imperial gallon.
The urban economy is measured using the test cycle known as ECE-15, first introduced in 1970 by EC Directive 70/220/EWG and finalized by EEC Directive 90/C81/01 in 1999. It simulates a 4,052 m (2.518 mile) urban trip at an average speed of 18.7 km/h (11.6 mph) and at a maximum speed of 50 km/h (31 mph).
The extra-urban driving cycle or EUDC lasts 400 seconds (6 minutes 40 seconds) at an average speed 62.6 km/h (39 mph) and a top speed of 120 km/h (74.6 mph).
[
45
]
EU fuel consumption numbers are often considerably lower than corresponding US EPA test results for the same vehicle. For example, the 2011
Honda CR-Z
with a six-speed manual transmission is rated 6.1/4.4 L/100 km in Europe
[
46
]
and 7.6/6.4 L/100 km (31/37 mpg ) in the United States.
[
47
]
In the European Union advertising has to show
carbon dioxide
(CO
2
)-emission and fuel consumption data in a clear way as described in the UK Statutory Instrument 2004 No 1661.
[
48
]
Since September 2005 a color-coded "Green Rating" sticker has been available in the UK, which rates fuel economy by CO
2
emissions: A: <= 100 g/km, B: 100–120, C: 121–150, D: 151–165, E: 166–185, F: 186–225, and G: 226+. Depending on the type of fuel used, for gasoline A corresponds to about 4.1 L/100 km (69 mpg
‑imp
; 57 mpg
‑US
) and G about 9.5 L/100 km (30 mpg
‑imp
; 25 mpg
‑US
).
[
49
]
Ireland has a very similar label, but the ranges are slightly different, with A: <= 120 g/km, B: 121–140, C: 141–155, D: 156–170, E: 171–190, F: 191–225, and G: 226+.
[
50
]
From 2020, EU requires manufacturers to average 95 g/km CO
2
emission or less, or pay an
excess emissions premium
.
[
51
]
In the UK the ASA (Advertising standards agency) have claimed that fuel consumption figures are misleading. Often the case with European vehicles as the MPG (miles per gallon) figures that can be advertised are often not the same as "real world" driving.
The ASA have said that car manufacturers can use "cheats" to prepare their vehicles for their compulsory fuel efficiency and emissions tests in a way set out to make themselves look as "clean" as possible. This practice is common in gasoline and diesel vehicle tests, but hybrid and electric vehicles are not immune as manufacturers apply these techniques to fuel efficiency.
Car experts
[
who?
]
also assert that the
official
MPG figures given by manufacturers do not represent the
true
MPG values from real-world driving.
[
52
]
Websites have been set up to show the real-world MPG figures, based on crowd-sourced data from real users, vs the official MPG figures.
[
53
]
The major loopholes in the current EU tests allow car manufacturers a number of "cheats" to improve results. Car manufacturers can:
Disconnect the alternator, thus no energy is used to recharge the battery;
Use special lubricants that are not used in production cars, in order to reduce friction;
Turn off all electrical gadgets i.e. Air Con/Radio;
Adjust brakes or even disconnect them to reduce friction;
Tape up cracks between body panels and windows to reduce air resistance;
Remove Wing mirrors.
[
54
]
According to the results of a 2014 study by the
International Council on Clean Transportation
(ICCT), the gap between official and real-world fuel-economy figures in Europe has risen to about 38% in 2013 from 10% in 2001. The analysis found that for private cars, the difference between on-road and official CO
2
values rose from around 8% in 2001 to 31% in 2013, and 45% for company cars in 2013. The report is based on data from more than half a million private and company vehicles across Europe. The analysis was prepared by the ICCT together with the
Netherlands Organization for Applied Scientific Research
(TNO), and the German Institut für Energie- und Umweltforschung Heidelberg (IFEU).
[
55
]
In 2018 update of the ICCT data the difference between the official and real figures was again 38%.
[
56
]
The evaluation criteria used in Japan reflects driving conditions commonly found, as the typical Japanese driver does not drive as fast as other regions internationally (
Speed limits in Japan
).
The 10–15 mode
driving cycle
test is the official fuel economy and emission certification test for new light duty vehicles in Japan. Fuel economy is expressed in km/L (kilometers per liter) and emissions are expressed in g/km. The test is carried out on a
dynamometer
and consist of 25 tests which cover idling, acceleration, steady running and deceleration, and simulate typical Japanese urban and/or expressway driving conditions. The running pattern begins with a warm start, lasts for 660 seconds (11 minutes) and runs at speeds up to 70 km/h (43.5 mph).
[
57
]
[
58
]
The distance of the cycle is 6.34 km (3.9 mi), average speed of 25.6 km/h (15.9 mph), and duration 892 seconds (14.9 minutes), including the initial 15 mode segment.
[
58
]
A new more demanding test, called the JC08, was established in December 2006 for Japan's new standard that goes into effect in 2015, but it is already being used by several car manufacturers for new cars. The JC08 test is significantly longer and more rigorous than the 10–15 mode test. The running pattern with JC08 stretches out to 1200 seconds (20 minutes), and there are both cold and warm start measurements and top speed is 82 km/h (51.0 mph). The economy ratings of the JC08 are lower than the 10–15 mode cycle, but they are expected to be more real world.
[
57
]
The
Toyota Prius
became the first car to meet Japan's new 2015 Fuel Economy Standards measured under the JC08 test.
[
59
]
Starting on 7 April 2008, all cars of up to 3.5 tonnes GVW sold other than private sale need to have a fuel economy sticker applied (if available) that shows the rating from one half star to six stars with the most economic cars having the most stars and the more fuel hungry cars the least, along with the fuel economy in L/100 km and the estimated annual fuel cost for driving 14,000 km (at present fuel prices). The stickers must also appear on vehicles to be leased for more than 4 months. All new cars currently rated range from 6.9 L/100 km (41 mpg
‑imp
; 34 mpg
‑US
) to 3.8 L/100 km (74 mpg
‑imp
; 62 mpg
‑US
) and received respectively from 4.5 to 5.5 stars.
[
60
]
The
Kingdom of Saudi Arabia
announced new light-duty vehicle fuel economy standards in November 2014 which became effective 1 January 2016 and will be fully phased in by 1 January 2018 (
Saudi Standards
regulation SASO-2864). A review of the targets will be carried by December 2018, at which time targets for 2021–2025 will be set.
Motor vehicle fuel economy from 1949 to 2021
The
Energy Tax Act
of 1978
[
61
]
in the US established a gas guzzler tax on the sale of new model year vehicles whose fuel economy fails to meet certain statutory levels. The tax applies only to cars (not trucks) and is collected by the
IRS
. Its purpose is to discourage the production and purchase of fuel-inefficient vehicles. The tax was phased in over ten years with rates increasing over time. It applies only to manufacturers and importers of vehicles, although presumably some or all of the tax is passed along to automobile consumers in the form of higher prices. Only new vehicles are subject to the tax, so no tax is imposed on used car sales. The tax is graduated to apply a higher tax rate for less-fuel-efficient vehicles. To determine the tax rate, manufacturers test all the vehicles at their laboratories for fuel economy. The US
Environmental Protection Agency
confirms a portion of those tests at an EPA lab.
In some cases, this tax may apply only to certain variants of a given model; for example, the 2004–2006
Pontiac GTO
(captive import version of the
Holden Monaro
) did incur the tax when ordered with the four-speed automatic transmission, but did not incur the tax when ordered with the six-speed manual transmission.
[
62
]
EPA testing procedure through 2007
[
edit
]
Two separate fuel economy tests simulate city driving and highway driving. The "city" driving cycle is based on the Urban Dynamometer Driving Schedule or (UDDS) or
FTP-72
, defined in
40 CFR
86.I
. The UDDS cycle starts with a cold engine and makes 23 stops over a period of 31 minutes for an average speed of 20 mph (32 km/h) and a top speed of 56 mph (90 km/h). The UDDS procedure has been updated to
FTP-75
by adding a "hot start" cycle which repeats the "cold start" cycle after a 10-minute pause.
The "highway" program or Highway Fuel Economy Driving Schedule (
HWFET
) is defined in
40 CFR
600.I
and uses a warmed-up engine and makes no stops, averaging 48 mph (77 km/h) with a top speed of 60 mph (97 km/h) over a 10-mile (16 km) distance. A weighted average of city (55%) and highway (45%) fuel economies is used to determine the combined rating and guzzler tax.
[
63
]
[
64
]
[
65
]
This rating is what is also used for light-duty vehicle
corporate average fuel economy
regulations.
Because EPA figures had almost always indicated better efficiency than real-world fuel-efficiency, the EPA has modified the method starting with 2008. Updated estimates are available for vehicles back to the 1985 model year.
[
63
]
[
66
]
The "city" or Urban Dynamometer Driving Schedule (UDDS) used in the EPA Federal Test Procedure
The Highway Fuel Economy Driving Cycle (HWFET) used in the EPA Federal Test Procedure
EPA testing procedure: 2008 and beyond
[
edit
]
2008
Monroney sticker
highlights fuel economy.
US EPA altered the testing procedure effective MY2008 which adds three new
Supplemental Federal Test Procedure
(SFTP) tests to include the influence of higher driving speed, harder acceleration, colder temperature and air conditioning use.
[
67
]
SFTP
US06
is a high speed/quick acceleration loop that lasts 10 minutes, covers 8 miles (13 km), averages 48 mph (77 km/h) and reaches a top speed of 80 mph (130 km/h). Four stops are included, and brisk acceleration maximizes at a rate of 8.46 mph (13.62 km/h) per second. The engine begins warm and air conditioning is not used. Ambient temperature varies between 68 °F (20 °C) to 86 °F (30 °C).
SFTP
SC03
is the air conditioning test, which raises ambient temperatures to 95 °F (35 °C), and puts the vehicle's climate control system to use. Lasting 9.9 minutes, the 3.6-mile (5.8 km) loop averages 22 mph (35 km/h) and maximizes at a rate of 54.8 mph (88.2 km/h). Five stops are included, idling occurs 19 percent of the time and acceleration of 5.1 mph per second is achieved. Engine temperatures begin warm.
Lastly, a cold temperature cycle uses the same parameters as the current city loop, except that ambient temperature is set to 20 °F (−7 °C).
EPA tests for fuel economy do not include electrical load tests beyond climate control, which may account for some of the discrepancy between EPA and real world fuel-efficiency. A 200 W electrical load can produce a 0.4 km/L (0.94 mpg) reduction in efficiency on the FTP 75 cycle test.
[
33
]
Beginning with model year 2017 the calculation method changed to improve the accuracy of the estimated 5-cycle city and highway fuel economy values derived from just the FTP and HFET tests, with lower uncertainty for fuel efficient vehicles.
[
68
]
Electric vehicles and hybrids
[
edit
]
2010
Monroney sticker
for a
plug-in hybrid
showing fuel economy in
all-electric mode
and gasoline-only mode
Following the efficiency claims made for vehicles such as
Chevrolet Volt
and
Nissan Leaf
, the
National Renewable Energy Laboratory
recommended to use EPA's new vehicle fuel efficiency formula that gives different values depending on fuel used.
[
69
]
In November 2010 the EPA introduced the first fuel economy ratings in the
Monroney stickers
for
plug-in electric vehicles
.
For the fuel economy label of the Chevy Volt
plug-in hybrid
EPA rated the car separately for
all-electric mode
expressed in
miles per gallon gasoline equivalent
(MPG-e) and for gasoline-only mode expressed in conventional miles per gallon. EPA also estimated an overall combined city/highway gas-electricity fuel economy rating expressed in miles per gallon gasoline equivalent (MPG-e). The label also includes a table showing fuel economy and electricity consumed for five different scenarios: 30 miles (48 km), 45 miles (72 km), 60 miles (97 km) and 75 miles (121 km) driven between a full charge, and a never charge scenario. This information was included to make the consumers aware of the variability of the fuel economy outcome depending on miles driven between charges. Also the fuel economy for a gasoline-only scenario (never charge) was included. For electric-only mode the energy consumption estimated in
kWh
per 100 miles (160 km) is also shown.
[
70
]
[
71
]
2010
Monroney label
showing the EPA's combined city/highway
fuel economy equivalent
for an all-
electric car
, in this case a 2010
Nissan Leaf
For the fuel economy label of the Nissan Leaf
electric car
EPA rated the combined fuel economy in terms of
miles per gallon gasoline equivalent
, with a separate rating for city and highway driving. This fuel economy equivalence is based on the energy consumption estimated in
kWh
per 100 miles, and also shown in the Monroney label.
[
72
]
In May 2011, the
National Highway Traffic Safety Administration
(NHTSA) and EPA issued a joint final rule establishing new requirements for a
fuel economy and environment label
that is mandatory for all new passenger cars and trucks starting with
model year
2013, and voluntary for 2012 models. The ruling includes new labels for
alternative fuel
and
alternative propulsion
vehicles available in the US market, such as
plug-in hybrids
,
electric vehicles
,
flexible-fuel vehicles
,
hydrogen fuel cell vehicle
, and
natural gas vehicles
.
[
73
]
[
74
]
The common fuel economy metric adopted to allow the comparison of alternative fuel and advanced technology vehicles with conventional
internal combustion engine
vehicles is
miles per gallon of gasoline equivalent
(MPGe). A gallon of gasoline equivalent means the number of kilowatt-hours of electricity, cubic feet of
compressed natural gas
(CNG), or kilograms of
hydrogen
that is equal to the energy in a gallon of gasoline.
[
73
]
The new labels also include for the first time an estimate of how much fuel or electricity it takes to drive 100 miles (160 km), providing US consumers with fuel consumption per distance traveled, the metric commonly used in many other countries. EPA explained that the objective is to avoid the traditional miles per gallon metric that can be potentially misleading when consumers compare fuel economy improvements, and known as the "MPG illusion"
[
75
]
– this illusion arises because the reciprocal (i.e. non-linear) relationship between cost (equivalently, volume of fuel consumed) per unit distance driven and MPG value means that
differences
in MPG values are not directly meaningful – only ratios are (in mathematical terms, the reciprocal function does not commute with addition and subtraction; in general, a difference in reciprocal values is not equal to the reciprocal of their difference). It has been claimed that many consumers are unaware of this, and therefore compare MPG values by subtracting them, which can give a misleading picture of relative differences in fuel economy between different pairs of vehicles – for instance, an increase from 10 to 20 MPG corresponds to a 100% improvement in fuel economy, whereas an increase from 50 to 60 MPG is only a 20% improvement, although in both cases the difference is 10 MPG.
[
76
]
The EPA explained that the new gallons-per-100-miles metric provides a more accurate measure of fuel efficiency
[
73
]
[
77
]
– notably, it is equivalent to the normal metric measurement of fuel economy, liters per 100 kilometers (L/100 km).
Curve of average car mileage for model years between 1978 and 2014
The Corporate Average Fuel Economy (CAFE) regulations in the United States, first enacted by Congress in 1975,
[
78
]
are federal regulations intended to improve the average fuel economy of cars and light trucks (trucks, vans and
sport utility vehicles
) sold in the US in the wake of the
1973 Arab Oil Embargo
. Historically, it is the sales-weighted average fuel economy of a manufacturer's
fleet
of current
model year
passenger cars or light trucks, manufactured for sale in the United States. Under Truck CAFE standards 2008–2011 this changes to a "footprint" model where larger trucks are allowed to consume more fuel. The standards were limited to vehicles under a certain weight, but those weight classes were expanded in 2011.
Federal and state regulations
[
edit
]
The
Clean Air Act
of 1970 prohibited states from establishing their own air pollution standards. However, the legislation authorized the EPA to grant a waiver to California, allowing the state to set higher standards.
[
79
]
The law provides a “piggybacking” provision that allows other states to adopt vehicle emission limits that are the same as California's.
[
80
]
California's waivers were routinely granted until 2007, when the
George W. Bush administration
rejected the state's bid to adopt global warming pollution limits for cars and light trucks.
[
81
]
California and 15 other states that were trying to put in place the same emissions standards sued in response.
[
82
]
The case was tied up in court until the
Obama administration
reversed the policy in 2009 by granting the waiver.
[
83
]
In August 2012, President Obama announced new standards for American-made automobiles of an average of 54.5 miles per gallon by the year 2025.
[
84
]
[
85
]
In April 2018, EPA Administrator
Scott Pruitt
announced that the
Trump administration
planned to roll back the 2012 federal standards and would also seek to curb California's authority to set its own standards.
[
79
]
Although the Trump administration was reportedly considering a compromise to allow state and national standards to stay in place,
[
86
]
on 21 February 2019 the White House declared that it had abandoned these negotiations.
[
87
]
A government report subsequently found that, in 2019, new light-duty vehicle fuel economy fell 0.2 miles per gallon (to 24.9 miles per gallon) and pollution increased 3 grams per mile traveled (to 356 grams per mile). A decrease in fuel economy and an increase in pollution had not occurred for the previous five years.
[
88
]
The Obama-era rule was officially rolled back on 31 March 2020 during the Trump administration,
[
89
]
but the rollback was reversed on 20 December 2021 during the Biden administration.
[
90
]
Fuel economy of trucks
[
edit
]
Trucks are usually bought as an investment good. They are meant to earn money. As the Diesel fuel burnt in heavy trucks accounts for around 30%
[
91
]
of the total costs for a freight forwarding company there is always a lot of interest in both the haulage industry and the truck builder industry to strive for best fuel economy. For truck buyers the fuel economy measured by standard procedures is only a first guideline. Professional trucking companies measure the fuel economy of their trucks and truck fleets in real usage. Fuel economy of trucks in real usage is determined by four important factors:
[
91
]
The truck technology that is constantly improved by the various OEMs. The driver's driving style contributes a lot to the real fuel economy (different from the test cycles where a standard driving style is used). The maintenance condition of the vehicle influences the fuel efficiency – again different from standardized procedures where the trucks are always presented in flawless condition. Last but not least the usage of the vehicle influences the fuel consumption: Hilly roads and heavy loads will increase the fuel consumption of a vehicle.
Effect on pollution
[
edit
]
Fuel efficiency directly affects emissions causing pollution by affecting the amount of fuel used. However, it also depends on the fuel source used to drive the vehicle concerned. Cars for example, can run on a number of fuel types other than gasoline, such as
natural gas
,
LPG
or
biofuel
or electricity which creates various quantities of atmospheric pollution.
A kilogram of carbon, whether contained in petrol, diesel, kerosene, or any other hydrocarbon fuel in a vehicle, leads to approximately 3.6 kg of
CO
2
emissions.
[
92
]
Due to the carbon content of gasoline, its combustion emits 2.3 kg/L (19.4 lb/US gal) of
CO
2
; since diesel fuel is more energy dense per unit volume, diesel emits 2.6 kg/L (22.2 lb/US gal).
[
92
]
This figure is only the CO
2
emissions of the final fuel product and does not include additional CO
2
emissions created during the drilling, pumping, transportation and refining steps required to produce the fuel. Additional measures to reduce overall emission includes improvements to the efficiency of
air conditioners
, lights and tires.
US Gallons
1 mpg ≈ 0.425 km/L
235.2/mpg ≈ L/100 km
1 mpg ≈ 1.201 mpg (imp)
Imperial gallons
1 mpg ≈ 0.354 km/L
282/mpg ≈ L/100 km
1 mpg ≈ 0.833 mpg (US)
Conversion from mpg
[
edit
]
mpg (imp)
mpg (US)
km/L
L/100 km
5
4.2
1.8
56.5
10
8.3
3.5
28.2
15
12.5
5.3
18.8
20
16.7
7.1
14.1
25
20.8
8.9
11.3
30
25.0
10.6
9.4
35
29.1
12.4
8.1
40
33.3
14.2
7.1
45
37.5
15.9
6.3
50
41.6
17.7
5.6
55
45.8
19.5
5.1
60
50.0
21.2
4.7
65
54.1
23.0
4.3
70
58.3
24.8
4.0
75
62.5
26.6
3.8
80
66.6
28.3
3.5
85
70.8
30.1
3.3
90
74.9
31.9
3.1
95
79.1
33.6
3.0
100
83.3
35.4
2.8
mpg (US)
mpg (imp)
km/L
L/100 km
5
6.0
2.1
47.0
10
12.0
4.3
23.5
15
18.0
6.4
15.7
20
24.0
8.5
11.8
25
30.0
10.6
9.4
30
36.0
12.8
7.8
35
42.0
14.9
6.7
40
48.0
17.0
5.9
45
54.0
19.1
5.2
50
60.0
21.3
4.7
55
66.1
23.4
4.3
60
72.1
25.5
3.9
65
78.1
27.6
3.6
70
84.1
29.8
3.4
75
90.1
31.9
3.1
80
96.1
34.0
2.9
85
102.1
36.1
2.8
90
108.1
38.3
2.6
95
114.1
40.4
2.5
100
120.1
42.5
2.4
Conversion from km/L and L/100 km
[
edit
]
L/100 km
km/L
mpg (US)
mpg (imp)
1
100.0
235.2
282.5
2
50.0
117.6
141.2
3
33.3
78.4
94.2
4
25.0
58.8
70.6
5
20.0
47.0
56.5
6
16.7
39.2
47.1
7
14.3
33.6
40.4
8
12.5
29.4
35.3
9
11.1
26.1
31.4
10
10.0
23.5
28.2
15
6.7
15.7
18.8
20
5.0
11.8
14.1
25
4.0
9.4
11.3
30
3.3
7.8
9.4
35
2.9
6.7
8.1
40
2.5
5.9
7.1
45
2.2
5.2
6.3
50
2.0
4.7
5.6
55
1.8
4.3
5.1
60
1.7
3.9
4.7
km/L
L/100 km
mpg (US)
mpg (imp)
5
20.0
11.8
14.1
10
10.0
23.5
28.2
15
6.7
35.3
42.4
20
5.0
47.0
56.5
25
4.0
58.8
70.6
30
3.3
70.6
84.7
35
2.9
82.3
98.9
40
2.5
94.1
113.0
45
2.2
105.8
127.1
50
2.0
117.6
141.2
55
1.8
129.4
155.4
60
1.7
141.1
169.5
65
1.5
152.9
183.6
70
1.4
164.7
197.7
75
1.3
176.4
211.9
80
1.3
188.2
226.0
85
1.2
199.9
240.1
90
1.1
211.7
254.2
95
1.1
223.5
268.4
100
1.0
235.2
282.5
Automobile costs
ACEA agreement
Battery electric vehicle
Car speed and energy consumption
Car tuning
Climate crisis
Emission standard
Energy conservation
Energy-efficient driving
FF layout
Fuel efficiency in transportation
Fuel saving devices
Gasoline gallon equivalent
Motorized quadricycle
(vehicles with low power engines/low top speed)
Miles per gallon gasoline equivalent
Passenger miles per gallon
The Very Light Car
Vehicle Efficiency Initiative
Vehicle metrics
Green vehicle
Low-carbon economy
Low-rolling resistance tires
Microcar
Plug-in hybrid
^
Specifically, the production-weighted
harmonic mean
^
The 2.2% drop figure was calculated by finding daily consumption to be 9,299,684 barrels of petroleum. Obtain 1973's petroleum consumption from transportation sector at 2.1e from the Energy Consumption by Sector section, then convert to barrels using A1 in the Thermal Conversion Factors section (assume "conventional motor gasoline" since ethanol-based or purportedly smog-reducing gas was not common in 1973).
[
14
]
^
Page, Walter Hines; Page, Arthur Wilson (1916).
"Man and His Machines"
.
The World's Work
. Vol. XXXIII. Garden City, New York: Doubleday, Page & Co.
^
"What counts as 'good' MPG nowadays?"
. 21 December 2016.
^
The New Fuel Economy Label
at FuelEconomy.gov
^
"Highlights of the Automotive Trends Report"
.
EPA.gov
. U.S. Environmental Protection Agency (EPA). 12 December 2022.
Archived
from the original on 2 September 2023.
^
Cazzola, Pierpaolo; Paoli, Leonardo; Teter, Jacob (November 2023).
"Trends in the Global Vehicle Fleet 2023 / Managing the SUV Shift and the EV Transition"
(PDF)
. Global Fuel Economy Initiative (GFEI). p. 3.
doi
:
10.7922/G2HM56SV
.
Archived
(PDF)
from the original on 26 November 2023.
^
Paul R. Portney; Ian W.H. Parry; Howard K. Gruenspecht; Winston Harrington (November 2003).
"The Economics of Fuel Economy Standards"
(PDF)
. Resources for the Future. Archived from
the original
(PDF)
on 1 December 2007
. Retrieved
4 January
2008
.
^
"Highlights of the Automotive Trends Report"
.
US EPA
. November 2021
. Retrieved
30 November
2021
.
^
"2019 Best and Worst Fuel Economy Vehicles"
. US EPA
. Retrieved
23 June
2019
.
^
Reducing CO2 emissions from passenger cars – Policies – Climate Action – European Commission
. Ec.europa.eu (9 December 2010). Retrieved 21 September 2011.
^
Myth: Cars are becoming more fuel efficient
. Ptua.org.au. Retrieved 21 September 2011.
^
a
b
c
Comparison of Passenger Vehicle Fuel Economy and GHG Emission Standards Around the World at Pew Center on Global Climate Change
Archived
13 April 2008 at the
Wayback Machine
. (PDF). Retrieved 21 September 2011.
^
a
b
c
Steady Speed Fuel Economy
Archived
24 September 2012 at the
Wayback Machine
"The two earlier studies by the Federal Highway Administration (FHWA) indicate maximum fuel efficiency was achieved at speeds of 35 to 40 mph (55 to 65 km/h). The recent FHWA study indicates greater fuel efficiency at higher speeds."
^
Cowan, Edward (27 November 1973). "Politics and Energy: Nixon's Silence on Rationing Reflects Hope That Austerity Can Be Avoided".
The New York Times
. p. 30.
^
Staff (28 June 2008).
Annual Energy Review
(PDF)
(2007 ed.). Washington, DC: Energy Information Administration. Archived from
the original
(PDF)
on 26 September 2018.
^
"55 Mile-per-hour Speed Limit Approved by House"
.
United Press International
. 4 December 1973. p. 30
. Retrieved
22 July
2008
.
(subscription required)
^
"Special Report 254: Managing Speed"
(PDF)
.
Transportation Research Board
: 189
. Retrieved
17 September
2014
.
Bloomquist (1984) estimated that the 1974 National Maximum Speed Limit (NMSL) reduced fuel consumption by 0.2 to 1.0 percent.
^
"Highway Statistics 1973 (Table VM-2: VEHICLE MILES, BY STATE AND HIGHWAY SYSTEM-1973)"
(PDF)
.
Federal Highway Administration
: 76. Archived from
the original
(PDF)
on 4 March 2013
. Retrieved
17 September
2014
.
^
a
b
"Lexus IS250 2.5L 6cyl, Auto 6 speed Sedan, 5 seats, 2WD"
.
{{
cite web
}}
: CS1 maint: deprecated archival service (
link
)
^
a
b
IS 250 Kraftstoffverbrauch kombiniert 8,9 L/100 km (innerorts 12,5 L/ außerorts 6,9 L) bei CO2-Emissionen von 209 g/km nach dem vorgeschriebenen EU-Messverfahren
"LEXUS – Lexus – IS – Sportlimousine – Cabriolet – Cabrio – Kabrio – Coupé – Coupe – Hochleistung IS F – High-Performance-Fahrzeug IS F"
. Archived from
the original
on 2 April 2010
. Retrieved
22 April
2010
.
^
a
b
2009 Lexus IS 250 6 cyl, 2.5 L, Automatic (S6), Premium
http://www.fueleconomy.gov/feg/findacar.htm
^
"Gas prices too high? Try Europe"
.
Christian Science Monitor
. 26 August 2005.
Archived
from the original on 18 September 2012.
^
"U.S. 'stuck in reverse' on fuel economy"
.
NBC News
. 28 February 2007. Archived from
the original
on 6 December 2014.
^
"VW Lupo: Rough road to fuel economy"
.
^
Heavy Vehicles and Characteristics
Archived
2012-07-23 at the
Wayback Machine
Table 5.4
^
Light Vehicles and Characteristics
Archived
2012-09-15 at the
Wayback Machine
Table 4.1
^
How Do Gasoline Prices Affect Fleet Fuel Economy?
Archived
2012-10-21 at the
Wayback Machine
^
Dee-Ann Durbin of the Associated Press, June 17, 2014, Mercury News,
Auto industry gets serious about lighter materials
Archived
2015-04-15 at the
Wayback Machine
, Retrieved April 11, 2015, "...Automakers have been experimenting for decades with lightweighting... the effort is gaining urgency with the adoption of tougher gas mileage standards. ..."
^
Yang, Zifei; Bandivadekar, Anup.
"Light-duty vehicle greenhouse gas and fuel economy standards"
(PDF)
. International Council on Clean Transportation
. Retrieved
1 December
2017
.
^
"Lexus IS – Driving in every sense"
.
Lexus Canada
.
^
"TRANSPORTATION RESEARCH BOARD SPECIAL REPORT 286 TIRES AND PASSENGER VEHICLE FUEL ECONOMY, Transportation Research Board, National Academy of Sciences p.62-65 of pdf, p.39-42 of the report. Retrieved 22 October 2014"
(PDF)
.
^
Wheels, online road load, and MPG calculator
. Virtual-car.org (3 August 2009). Retrieved 21 September 2011.
^
An Overview of Current Automatic, Manual and Continuously Variable Transmission Efficiencies and Their Projected Future Improvements
. SAE.org (1 March 1999). Retrieved 21 September 2011.
^
a
b
Automotive Electrical Systems Circa 2005
Archived
3 February 2009 at the
Wayback Machine
. Spectrum.ieee.org. Retrieved 21 September 2011.
^
Low-rolling resistance tires
^
Chandler, David (9 February 2009).
"More power from bumps in the road"
. Retrieved
8 October
2009
.
^
Gas Saving and Emission Reduction Devices Evaluation | Cars and Light Trucks | US EPA
. Epa.gov. Retrieved 21 September 2011.
^
https://onfuel.appspot.com
keep track of fuel efficiency
^
"Anglian Water spot on with pressure test"
.
Tyrepress
. 29 October 2015
. Retrieved
30 October
2015
.
^
Chinese Fuel Economy Laws
. Treehugger.com. Retrieved 21 September 2011.
^
Cox, Lisa (30 March 2019).
"
'Woefully dirty': Government accused over Australia's failure to cut vehicle emissions"
.
The Guardian
.
^
Vehicles & the Environment
. Infrastructure.gov.au. Retrieved 21 September 2011.
^
Information on Green Vehicle Guide Ratings and Measurement
. Australian Department of Infrastructure and Transport
^
Green Vehicle Guide
Archived
22 April 2006 at the
Wayback Machine
. Green Vehicle Guide. Retrieved 21 September 2011.
^
a
b
"5-cycle testing"
.
nrcan.gc.ca
. 30 April 2018.
^
Vehicle test cycles
. Herkules.oulu.fi. Retrieved 21 September 2011.
^
"News & Events"
.
www.honda.de
. Retrieved
2 May
2023
.
^
"2011 Honda CR-Z Specs and Features"
. Retrieved
2 May
2023
.
[
permanent dead link
]
^
Guidance notes and examples
Archived
13 April 2008 at the
Wayback Machine
. (PDF). Retrieved 21 September 2011.
^
Fuel Economy Label
Archived
14 August 2008 at the
Wayback Machine
. Dft.gov.uk. Retrieved 21 September 2011.
^
Vehicle Labelling
Archived
7 July 2008 at the
Wayback Machine
. Environ.ie (1 July 2008). Retrieved 21 September 2011.
^
"Regulation (EU) 2019/631 of the European Parliament and of the Council of 17 April 2019 setting CO2 emission performance standards for new passenger cars and for new light commercial vehicles, and repealing Regulations (EC) No 443/2009 and (EU) No 510/2011 (Text with EEA relevance.)"
.
European Union
. 25 April 2019.
Annex 1, Part A.6 NEDC2020, Fleet Target is 95 g/km. (45) Manufacturers whose average specific emissions of CO2 exceed those permitted under this Regulation should pay an excess emissions premium with respect to each calendar year.
^
"Why the EC figures do not represent true MPG"
.
Honest John
. Retrieved
14 November
2015
.
^
"Real Life Fuel Economy (MPG) Register"
.
Honest John
. Retrieved
14 November
2015
.
^
"Cars and Garages: Diagnose Problems, Estimate Costs & Find Garages"
.
carsandgarages.co.uk
.
^
Mike Millikin (28 September 2014).
"ICCT: gap between official and real-world fuel economy figures in Europe reaches ~38%; call to implement WLTP ASAP"
.
Green Car Congress
. Retrieved
28 September
2014
.
^
From laboratory to road: A 2018 update
ICCT, 2019
^
a
b
Japan Automobile Manufacturers Association
(JAMA) (2009).
"From 10•15 to JC08: Japan's new economy formula"
. News from JAMA
. Retrieved
9 April
2012
.
Issue No. 2, 2009
.
^
a
b
"Japanese 10–15 Mode"
. Diesel.net
. Retrieved
9 April
2012
.
^
"Prius Certified to Japanese 2015 Fuel Economy Standards with JC08 Test Cycle"
.
Green Car Congress
. 11 August 2007
. Retrieved
9 April
2012
.
^
"Vehicle Fuel Economy Labelling – FAQs"
. Archived from
the original
on 10 July 2008
. Retrieved
2 May
2023
.
^
Frequently Asked Questions
. Fueleconomy.gov. Retrieved 21 September 2011.
^
Steven Cole Smith (28 April 2005).
"2005 Pontiac GTO"
. Orlando Sentinel via Cars.com. Archived from
the original
on 11 May 2015
. Retrieved
21 February
2011
.
^
a
b
"Dynamometer Driver's Aid"
. US EPA. Archived from
the original
on 30 March 2014
. Retrieved
11 January
2011
.
^
How the EPA Tests and Rates Fuel Economy
. Auto.howstuffworks.com (7 September 2005). Retrieved 21 September 2011.
^
Gasoline Vehicles: Learn More About the Label
. Retrieved 10 July 2020.
^
Find a Car 1985 to 2009
. Fueleconomy.gov. Retrieved 21 September 2011.
^
"2008 Ratings Changes"
. US EPA
. Retrieved
17 April
2013
.
^
US EPA United States Environmental Protection Agency.
"Basic Search"
. Iaspub.epa.gov. Archived from
the original
on 22 January 2017
. Retrieved
1 September
2022
.
^
Roth, Dan. (1 October 2009)
REPORT: EPA planning to address outlandish fuel economy claims of electric cars
. Autoblog.com. Retrieved 21 September 2011.
^
"Volt receives EPA ratings and label: 93 mpg-e all-electric, 37 mpg gas-only, 60 mpg-e combined"
.
Green Car Congress
. 24 November 2010
. Retrieved
24 November
2010
.
^
US Environmental Protection Agency
and
US Department of Energy
(4 May 2011).
"2011 Chevrolet Volt"
. Fueleconomy.gov
. Retrieved
21 May
2011
.
^
Nick Bunkley (22 November 2010).
"Nissan Says Its Electric Leaf Gets Equivalent of 99 M.P.G."
The New York Times
. Retrieved
23 November
2010
.
^
a
b
c
EPA (May 2011).
"Fact Sheet: New Fuel Economy and Environment Labels for a New Generation of Vehicles"
.
US Environmental Protection Agency
. Archived from
the original
on 29 May 2011
. Retrieved
25 May
2011
.
EPA-420-F-11-017
^
"EPA, DOT unveil the next generation of fuel economy labels"
.
Green Car Congress
. 25 May 2011
. Retrieved
25 May
2011
.
^
"Not All Fuel Efficiency Is Equal: Understanding the Miles-Per-Gallon Illusion"
.
Bloomberg.com
. 14 January 2014. Archived from
the original
on 15 January 2014
. Retrieved
11 November
2014
.
^
"The MPG Illusion"
. 3 June 2013
. Retrieved
11 November
2014
.
^
John M. Broder (25 May 2011).
"New Mileage Stickers Include Greenhouse Gas Data"
.
The New York Times
. Retrieved
26 May
2011
.
^
"CAFE Overview: "What is the origin of CAFE?"
"
. NHTSA. Archived from
the original
on 3 February 2009
. Retrieved
9 July
2008
.
^
a
b
Tabuchi, Hiroko
(2 April 2018).
"Calling car pollution standards 'too high,' EPA sets up fight with California"
.
The New York Times
.
^
Giovinazzo, Christopher (September 2003).
"California's Global Warming Bill: Will Fuel Economy Preemption Curb California's Air Pollution Leadership"
.
Ecology Law Quarterly
.
30
(4):
901–
902.
^
Tabuchi, Hiroko (19 December 2007).
"EPA Denies California's Emissions Waiver"
.
The New York Times
.
^
Richburg, Keith (3 January 2008).
"California Sues EPA Over Emissions Rules"
.
The Washington Post
.
^
Wang, Ucilia (30 June 2009).
"EPA grants California emissions waiver"
.
Greentech Media
.
^
"Obama Administration Finalizes Historic 54.5 MPG Fuel Efficiency Standards"
. White House. 28 August 2012
. Retrieved
28 November
2019
.
^
Fraser, Laura (Winter 2012–2013). "Shifting Gears".
NRDC's OnEarth
. p. 63.
^
Tabuchi, Hiroko (5 April 2018).
"Quietly, Trump officials and California seek deal on emissions"
.
The New York Times
.
^
Phillips, Anna M. (21 February 2019).
"Trump administration confirms it has ended fuel-economy talks with California"
.
Los Angeles Times
. Retrieved
11 May
2019
.
^
Associated Press (6 January 2021).
"For first time in 5 years, US gas mileage down, emissions up"
.
Orange County Register
. Retrieved
7 January
2021
.
^
"Trump rollback of mileage standards guts climate change push"
.
Yahoo News
. 31 March 2020
. Retrieved
2 May
2023
.
^
Kaufman, Alexander; D'Angelo, Chris (20 December 2021).
"EPA Reverses Trump's Fuel Mileage Rules On New Cars"
.
HuffPost
. Retrieved
20 December
2021
.
^
a
b
Hilgers, Michael (2021).
Commercial Vehicle Technology: Fuel consumption and consumption optimization
. Wilfried Achenbach. Berlin.
ISBN
978-3-662-60841-8
.
OCLC
1237865094
.
{{
cite book
}}
: CS1 maint: location missing publisher (
link
)
^
a
b
"Emission Facts: Average Carbon Dioxide Emissions Resulting from Gasoline and Diesel Fuel"
.
Office of Transportation and Air Quality
.
United States Environmental Protection Agency
. February 2005. Archived from
the original
on 28 February 2009
. Retrieved
28 July
2009
.
Real fuel consumption by user reports
Model Year 2014 Fuel Economy Guide
,
U.S. Environmental Protection Agency
and
U.S. Department of Energy
, April 2014.
Fuel Efficiency in Electric, Hybrid and Petrol Cars – Model Year 2019
Fuel Consumption Calculator Online |
| Markdown | [Jump to content](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#bodyContent)
Main menu
Main menu
move to sidebar
hide
Navigation
- [Main page](https://en.wikipedia.org/wiki/Main_Page "Visit the main page [z]")
- [Contents](https://en.wikipedia.org/wiki/Wikipedia:Contents "Guides to browsing Wikipedia")
- [Current events](https://en.wikipedia.org/wiki/Portal:Current_events "Articles related to current events")
- [Random article](https://en.wikipedia.org/wiki/Special:Random "Visit a randomly selected article [x]")
- [About Wikipedia](https://en.wikipedia.org/wiki/Wikipedia:About "Learn about Wikipedia and how it works")
- [Contact us](https://en.wikipedia.org/wiki/Wikipedia:Contact_us "How to contact Wikipedia")
Contribute
- [Help](https://en.wikipedia.org/wiki/Help:Contents "Guidance on how to use and edit Wikipedia")
- [Learn to edit](https://en.wikipedia.org/wiki/Help:Introduction "Learn how to edit Wikipedia")
- [Community portal](https://en.wikipedia.org/wiki/Wikipedia:Community_portal "The hub for editors")
- [Recent changes](https://en.wikipedia.org/wiki/Special:RecentChanges "A list of recent changes to Wikipedia [r]")
- [Upload file](https://en.wikipedia.org/wiki/Wikipedia:File_upload_wizard "Add images or other media for use on Wikipedia")
- [Special pages](https://en.wikipedia.org/wiki/Special:SpecialPages "A list of all special pages [q]")
[  ](https://en.wikipedia.org/wiki/Main_Page)
[Search](https://en.wikipedia.org/wiki/Special:Search "Search Wikipedia [f]")
Appearance
- [Donate](https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en)
- [Create account](https://en.wikipedia.org/w/index.php?title=Special:CreateAccount&returnto=Fuel+economy+in+automobiles "You are encouraged to create an account and log in; however, it is not mandatory")
- [Log in](https://en.wikipedia.org/w/index.php?title=Special:UserLogin&returnto=Fuel+economy+in+automobiles "You're encouraged to log in; however, it's not mandatory. [o]")
Personal tools
- [Donate](https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en)
- [Create account](https://en.wikipedia.org/w/index.php?title=Special:CreateAccount&returnto=Fuel+economy+in+automobiles "You are encouraged to create an account and log in; however, it is not mandatory")
- [Log in](https://en.wikipedia.org/w/index.php?title=Special:UserLogin&returnto=Fuel+economy+in+automobiles "You're encouraged to log in; however, it's not mandatory. [o]")
## Contents
move to sidebar
hide
- [(Top)](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles)
- [1 Quantities and units of measure](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Quantities_and_units_of_measure)
- [2 Statistics](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Statistics)
Toggle Statistics subsection
- [2\.1 Speed and fuel economy studies](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Speed_and_fuel_economy_studies)
- [2\.2 Discussion of statistics](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Discussion_of_statistics)
- [2\.3 Differences in testing standards](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Differences_in_testing_standards)
- [3 Energy considerations](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Energy_considerations)
Toggle Energy considerations subsection
- [3\.1 Fuel economy-boosting technologies](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Fuel_economy-boosting_technologies)
- [3\.1.1 Engine-specific technology](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Engine-specific_technology)
- [3\.1.2 Other vehicle technologies](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Other_vehicle_technologies)
- [3\.1.3 Future technologies](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Future_technologies)
- [3\.2 Fuel economy maximizing behaviors](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Fuel_economy_maximizing_behaviors)
- [3\.3 Fuel economy as part of quality management regimes](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Fuel_economy_as_part_of_quality_management_regimes)
- [4 Fuel economy standards and testing procedures](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Fuel_economy_standards_and_testing_procedures)
Toggle Fuel economy standards and testing procedures subsection
- [4\.1 Australia](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Australia)
- [4\.2 Canada](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Canada)
- [4\.3 Europe](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Europe)
- [4\.4 Japan](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Japan)
- [4\.4.1 10–15 mode](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#10%E2%80%9315_mode)
- [4\.4.2 JC08](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#JC08)
- [4\.5 New Zealand](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#New_Zealand)
- [4\.6 Saudi Arabia](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Saudi_Arabia)
- [4\.7 United States](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#United_States)
- [4\.7.1 US Energy Tax Act](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#US_Energy_Tax_Act)
- [4\.7.2 EPA testing procedure through 2007](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#EPA_testing_procedure_through_2007)
- [4\.7.3 EPA testing procedure: 2008 and beyond](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#EPA_testing_procedure:_2008_and_beyond)
- [4\.7.4 Electric vehicles and hybrids](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Electric_vehicles_and_hybrids)
- [4\.7.5 CAFE standards](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#CAFE_standards)
- [4\.7.6 Federal and state regulations](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Federal_and_state_regulations)
- [5 Fuel economy of trucks](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Fuel_economy_of_trucks)
- [6 Effect on pollution](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Effect_on_pollution)
- [7 Unit conversions](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Unit_conversions)
Toggle Unit conversions subsection
- [7\.1 Conversion from mpg](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Conversion_from_mpg)
- [7\.2 Conversion from km/L and L/100 km](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Conversion_from_km/L_and_L/100_km)
- [8 See also](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#See_also)
- [9 Annotations](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Annotations)
- [10 References](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#References)
- [11 External links](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#External_links)
Toggle the table of contents
# Fuel economy in automobiles
19 languages
- [العربية](https://ar.wikipedia.org/wiki/%D8%A7%D8%B3%D8%AA%D9%87%D9%84%D8%A7%D9%83_%D8%A7%D9%84%D9%88%D9%82%D9%88%D8%AF_%D8%A8%D8%A7%D9%84%D8%AA%D9%86%D9%83%D8%A9 "استهلاك الوقود بالتنكة – Arabic")
- [Български](https://bg.wikipedia.org/wiki/%D0%A0%D0%B0%D0%B7%D1%85%D0%BE%D0%B4_%D0%BD%D0%B0_%D0%B3%D0%BE%D1%80%D0%B8%D0%B2%D0%BE_%D0%BD%D0%B0_%D0%9C%D0%9F%D0%A1 "Разход на гориво на МПС – Bulgarian")
- [Català](https://ca.wikipedia.org/wiki/Consum_\(automoci%C3%B3\) "Consum (automoció) – Catalan")
- [کوردی](https://ckb.wikipedia.org/wiki/%D8%B3%DB%95%D8%B1%D9%81%DA%A9%D8%B1%D8%AF%D9%86%DB%8C_%D8%B3%D9%88%D9%88%D8%AA%DB%95%D9%85%DB%95%D9%86%DB%8C_%D9%84%DB%95_%D8%A6%DB%86%D8%AA%DB%86%D9%85%DB%86%D8%A8%DB%8C%D9%84%DB%95%DA%A9%D8%A7%D9%86 "سەرفکردنی سووتەمەنی لە ئۆتۆمۆبیلەکان – Central Kurdish")
- [Čeština](https://cs.wikipedia.org/wiki/Spot%C5%99eba_automobilu "Spotřeba automobilu – Czech")
- [Deutsch](https://de.wikipedia.org/wiki/Kraftstoffverbrauch "Kraftstoffverbrauch – German")
- [Español](https://es.wikipedia.org/wiki/Econom%C3%ADa_de_combustible_en_autom%C3%B3viles "Economía de combustible en automóviles – Spanish")
- [فارسی](https://fa.wikipedia.org/wiki/%D9%85%D8%B5%D8%B1%D9%81_%D8%B3%D9%88%D8%AE%D8%AA_%D8%AF%D8%B1_%D8%AE%D9%88%D8%AF%D8%B1%D9%88 "مصرف سوخت در خودرو – Persian")
- [Suomi](https://fi.wikipedia.org/wiki/Ajoneuvon_polttoaineenkulutus "Ajoneuvon polttoaineenkulutus – Finnish")
- [Français](https://fr.wikipedia.org/wiki/Consommation_de_carburant_des_v%C3%A9hicules_automobiles "Consommation de carburant des véhicules automobiles – French")
- [日本語](https://ja.wikipedia.org/wiki/%E7%87%83%E8%B2%BB "燃費 – Japanese")
- [한국어](https://ko.wikipedia.org/wiki/%EC%97%B0%EB%B9%84 "연비 – Korean")
- [Nederlands](https://nl.wikipedia.org/wiki/Brandstofverbruik "Brandstofverbruik – Dutch")
- [Norsk bokmål](https://no.wikipedia.org/wiki/Drivstofforbruk_for_kj%C3%B8ret%C3%B8y "Drivstofforbruk for kjøretøy – Norwegian Bokmål")
- [Русский](https://ru.wikipedia.org/wiki/%D0%A0%D0%B0%D1%81%D1%85%D0%BE%D0%B4_%D1%82%D0%BE%D0%BF%D0%BB%D0%B8%D0%B2%D0%B0_%D0%B0%D0%B2%D1%82%D0%BE%D0%BC%D0%BE%D0%B1%D0%B8%D0%BB%D0%B5%D0%B9 "Расход топлива автомобилей – Russian")
- [Slovenčina](https://sk.wikipedia.org/wiki/Spotreba_paliva_\(automobil\) "Spotreba paliva (automobil) – Slovak")
- [Svenska](https://sv.wikipedia.org/wiki/Br%C3%A4nslef%C3%B6rbrukning "Bränsleförbrukning – Swedish")
- [Українська](https://uk.wikipedia.org/wiki/%D0%95%D0%BA%D0%BE%D0%BD%D0%BE%D0%BC%D1%96%D1%8F_%D0%BF%D0%B0%D0%BB%D0%B8%D0%B2%D0%B0_%D0%B2_%D0%B0%D0%B2%D1%82%D0%BE%D0%BC%D0%BE%D0%B1%D1%96%D0%BB%D1%8F%D1%85 "Економія палива в автомобілях – Ukrainian")
- [中文](https://zh.wikipedia.org/wiki/%E6%B1%BD%E8%BD%A6%E7%87%83%E6%B2%B9%E7%BB%8F%E6%B5%8E%E6%80%A7 "汽车燃油经济性 – Chinese")
[Edit links](https://www.wikidata.org/wiki/Special:EntityPage/Q931507#sitelinks-wikipedia "Edit interlanguage links")
- [Article](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles "View the content page [c]")
- [Talk](https://en.wikipedia.org/wiki/Talk:Fuel_economy_in_automobiles "Discuss improvements to the content page [t]")
English
- [Read](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles)
- [Edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit "Edit this page [e]")
- [View history](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=history "Past revisions of this page [h]")
Tools
Tools
move to sidebar
hide
Actions
- [Read](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles)
- [Edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit "Edit this page [e]")
- [View history](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=history)
General
- [What links here](https://en.wikipedia.org/wiki/Special:WhatLinksHere/Fuel_economy_in_automobiles "List of all English Wikipedia pages containing links to this page [j]")
- [Related changes](https://en.wikipedia.org/wiki/Special:RecentChangesLinked/Fuel_economy_in_automobiles "Recent changes in pages linked from this page [k]")
- [Upload file](https://en.wikipedia.org/wiki/Wikipedia:File_Upload_Wizard "Upload files [u]")
- [Permanent link](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&oldid=1341142358 "Permanent link to this revision of this page")
- [Page information](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=info "More information about this page")
- [Cite this page](https://en.wikipedia.org/w/index.php?title=Special:CiteThisPage&page=Fuel_economy_in_automobiles&id=1341142358&wpFormIdentifier=titleform "Information on how to cite this page")
- [Get shortened URL](https://en.wikipedia.org/w/index.php?title=Special:UrlShortener&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FFuel_economy_in_automobiles)
Print/export
- [Download as PDF](https://en.wikipedia.org/w/index.php?title=Special:DownloadAsPdf&page=Fuel_economy_in_automobiles&action=show-download-screen "Download this page as a PDF file")
- [Printable version](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&printable=yes "Printable version of this page [p]")
In other projects
- [Wikimedia Commons](https://commons.wikimedia.org/wiki/Category:Fuel_economy_in_automobiles)
- [Wikidata item](https://www.wikidata.org/wiki/Special:EntityPage/Q931507 "Structured data on this page hosted by Wikidata [g]")
Appearance
move to sidebar
hide
From Wikipedia, the free encyclopedia
Distance traveled by a vehicle compared to volume of fuel consumed
[](https://en.wikipedia.org/wiki/File:CAFE_performance.svg)
New light-duty vehicle fuel economy by vehicle type from vehicle manufacturers in the United States, in miles per gallon (1975 - 2019)
[](https://en.wikipedia.org/wiki/File:2006_Honda_Airwave_fuel_efficiency_meter.jpg)
Fuel consumption monitor from a 2006 [Honda Airwave](https://en.wikipedia.org/wiki/Honda_Airwave "Honda Airwave"). The displayed fuel economy is 18.1 km/L (5.5 L/100 km; 43 mpg‑US).
[](https://en.wikipedia.org/wiki/File:Fuel_Economy,_1916.jpg)
A [Briggs and Stratton Flyer](https://en.wikipedia.org/wiki/Briggs_and_Stratton_Flyer "Briggs and Stratton Flyer") from 1916. Originally an experiment in creating a fuel-saving automobile in the United States, the vehicle weighed only 135 lb (61.2 kg) and was an adaptation of a small gasoline engine originally designed to power a bicycle.[\[1\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-1)
The **fuel economy** or **fuel efficiency** of an [automobile](https://en.wikipedia.org/wiki/Car "Car") relates to the [distance traveled](https://en.wikipedia.org/wiki/Distance_traveled "Distance traveled") by a vehicle and the amount of [fuel](https://en.wikipedia.org/wiki/Fuel "Fuel") consumed. It can be expressed in terms of the volume of fuel to travel a given distance, such as in **litres per 100 kilometres** (L/100 km), or through its inverse, the distance traveled per unit volume of fuel consumed, as in **kilometres per litre** (km/L) or **miles per gallon** (mpg). Since fuel economy of vehicles is a significant factor in [air pollution](https://en.wikipedia.org/wiki/Air_pollution "Air pollution"), the importation of [motor fuel](https://en.wikipedia.org/wiki/Motor_fuel "Motor fuel") can be a large part of a nation's [foreign trade](https://en.wikipedia.org/wiki/Foreign_trade "Foreign trade") and consumers frequently undervalue fuel efficiency, many countries impose requirements for fuel economy.
Different methods are used to approximate the actual performance of the vehicle. The energy in fuel is required to overcome various losses ([wind resistance](https://en.wikipedia.org/wiki/Wind_resistance "Wind resistance"), [tire drag](https://en.wikipedia.org/wiki/Tire_drag "Tire drag"), and others) encountered while propelling the vehicle, and in providing power to vehicle systems such as ignition or air conditioning. Various strategies can be employed to reduce losses at each of the conversions between the [chemical energy](https://en.wikipedia.org/wiki/Chemical_energy "Chemical energy") in the fuel and the [kinetic energy](https://en.wikipedia.org/wiki/Kinetic_energy "Kinetic energy") of the vehicle. Driver behavior can affect fuel economy; maneuvers such as sudden acceleration and heavy [braking](https://en.wikipedia.org/wiki/Braking "Braking") waste energy.
[Electric cars](https://en.wikipedia.org/wiki/Electric_car "Electric car") use [kilowatt-hours](https://en.wikipedia.org/wiki/Kilowatt-hours "Kilowatt-hours") of electricity per 100 kilometres (kWh/100km); in the U.S., an equivalence measure, such as [miles per gallon gasoline equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent "Miles per gallon gasoline equivalent") (US gallon) has been created to attempt to compare them.
## Quantities and units of measure
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=1 "Edit section: Quantities and units of measure")\]
[](https://en.wikipedia.org/wiki/File:Chart_MPG_to_L-100km_v2009-10-08.svg)
Conversion from mpg to L/100 km: blue - US [gallon](https://en.wikipedia.org/wiki/Gallon "Gallon"); red - UK gallon (imperial)
The fuel efficiency of motor vehicles can be expressed in multiple ways:
- **Fuel consumption** is the fuel used per unit distance; for example, **[litres](https://en.wikipedia.org/wiki/Litre "Litre") per 100 [kilometres](https://en.wikipedia.org/wiki/Kilometre "Kilometre") (L/100 km)**. The **lower** the value, the more economic a vehicle is; this is the measure generally used across [Europe](https://en.wikipedia.org/wiki/Europe "Europe") (except the UK, Denmark and The Netherlands - see below), [Africa](https://en.wikipedia.org/wiki/Africa "Africa"), [New Zealand](https://en.wikipedia.org/wiki/New_Zealand "New Zealand"), [Australia](https://en.wikipedia.org/wiki/Australia "Australia"), and [Canada](https://en.wikipedia.org/wiki/Canada "Canada"), [Uruguay](https://en.wikipedia.org/wiki/Uruguay "Uruguay"), [Paraguay](https://en.wikipedia.org/wiki/Paraguay "Paraguay"), [Guatemala](https://en.wikipedia.org/wiki/Guatemala "Guatemala"), [Colombia](https://en.wikipedia.org/wiki/Colombia "Colombia"), [China](https://en.wikipedia.org/wiki/China "China"), and [Madagascar](https://en.wikipedia.org/wiki/Madagascar "Madagascar"), and in the former [CIS](https://en.wikipedia.org/wiki/Commonwealth_of_Independent_States "Commonwealth of Independent States") states. \[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\],
- **Fuel economy** is the distance travelled per unit volume of fuel used; for example, **kilometres per litre (km/L)** or **[miles](https://en.wikipedia.org/wiki/Mile "Mile") per [gallon](https://en.wikipedia.org/wiki/Gallon "Gallon") (MPG)**. The **higher** the value, the more economic a vehicle is (the more distance it can travel with a certain volume of fuel). This measure is popular in the US and the UK (mpg), but in Europe, India, Japan, South Korea the metric unit *km/L* is used instead.
The formula for converting to miles per US gallon (3.7854 L) from L/100 km is 235\.215 x {\\displaystyle \\textstyle {\\frac {235.215}{x}}} , where x {\\displaystyle x}  is value of L/100 km. For miles per Imperial gallon (4.5461 L) the formula is 282\.481 x {\\displaystyle \\textstyle {\\frac {282.481}{x}}} .
Europe now uses the [WLTP](https://en.wikipedia.org/wiki/Worldwide_Harmonised_Light_Vehicles_Test_Procedure "Worldwide Harmonised Light Vehicles Test Procedure") standard to compare the fuel economy of all new vehicles.
Fuel economy can be expressed in two ways:
Units of fuel per fixed distance
Generally expressed in liters per 100 kilometers (L/100 km), used in most European countries, Canada, China, South Africa, Australia and New Zealand. Irish law allows for the use of miles per imperial [gallon](https://en.wikipedia.org/wiki/Gallon "Gallon"), alongside liters per 100 kilometers.[\[2\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-2) Liters per 100 kilometers may be used alongside miles per imperial [gallon](https://en.wikipedia.org/wiki/Gallon "Gallon") in the UK. The [window sticker](https://en.wikipedia.org/wiki/Monroney_sticker "Monroney sticker") on new US cars displays the vehicle's fuel consumption in US gallons per 100 miles, in addition to the traditional mpg number.[\[3\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-3) A lower number means more efficient, while a higher number means less efficient.
Units of distance per fixed fuel unit
Miles per [gallon](https://en.wikipedia.org/wiki/Gallon "Gallon") (mpg) are commonly used in the United States, the United Kingdom, and Canada (alongside L/100 km). Kilometers per liter (km/L) are more commonly used elsewhere in the Americas, Asia, parts of Africa and Oceania. In the [Levant](https://en.wikipedia.org/wiki/Levant "Levant") km/20 L is used, known as kilometers per *[tanaka](https://en.wiktionary.org/wiki/%D8%AA%D9%86%D9%83%D8%A9 "wikt:تنكة")*, a [metal container](https://en.wikipedia.org/wiki/Jerrycan "Jerrycan") which has a volume of twenty liters.\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\] When mpg is used, it is necessary to identify the type of gallon: the imperial gallon is 4.54609 liters, and the U.S. gallon is 3.785 liters. When using a measure expressed as distance per fuel unit, a higher number means more efficient, while a lower number means less efficient.
**Conversions of units:**
| | |
|---|---|
| Miles per **US** gallon → L/100 km: | 235 m p g U S \= 1 L / 100 k m {\\displaystyle {\\frac {235}{\\rm {mpg\_{US}}}}={\\rm {1\\;L/100\\;km}}}  |
## Statistics
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=2 "Edit section: Statistics")\]
[](https://en.wikipedia.org/wiki/File:1975-_US_vehicle_production_share,_by_vehicle_type.svg)
Trucks' share of US vehicles produced, has tripled since 1975. Though vehicle fuel efficiency has increased within each category, the overall trend toward less efficient types of vehicles has offset some of the benefits of greater fuel economy and reduction of carbon dioxide emissions.[\[4\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA_AutomotiveTrends_202212-4) Without the shift towards SUVs, energy use per unit distance could have fallen 30% more than it did from 2010 to 2022.[\[5\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-GlobalFuelEfficInit_202311-5)
While the [thermal efficiency](https://en.wikipedia.org/wiki/Thermal_efficiency "Thermal efficiency") (mechanical output to chemical energy in fuel) of petroleum [engines](https://en.wikipedia.org/wiki/Internal_combustion_engine "Internal combustion engine") has increased since the beginning of the [automotive era](https://en.wikipedia.org/wiki/History_of_the_automobile "History of the automobile"), this is not the only factor in fuel economy. The design of automobile as a whole and usage pattern affects the fuel economy. Published fuel economy is subject to variation between jurisdiction due to variations in testing protocols.
One of the first studies to determine fuel economy in the United States was the [Mobil Economy Run](https://en.wikipedia.org/wiki/Mobil_Economy_Run "Mobil Economy Run"), which was an event that took place every year from 1936 (except during [World War II](https://en.wikipedia.org/wiki/World_War_II "World War II")) to 1968. It was designed to provide real, efficient [fuel efficiency](https://en.wikipedia.org/wiki/Fuel_efficiency "Fuel efficiency") numbers during a coast-to-coast test on real roads and with regular traffic and weather conditions. The [Mobil](https://en.wikipedia.org/wiki/Mobil "Mobil") Oil Corporation sponsored it and the [United States Auto Club](https://en.wikipedia.org/wiki/United_States_Auto_Club "United States Auto Club") (USAC) sanctioned and operated the run. In more recent studies, the average fuel economy for new passenger car in the United States improved from 17 mpg (13.8 L/100 km) in 1978 to 22 mpg (10.7 L/100 km) in 1982.[\[6\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-6) The average[\[a\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-7) fuel economy for new 2020 model year cars, light trucks and SUVs in the United States was 25.4 miles per US gallon (9.3 L/100 km).[\[7\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-8) 2019 model year cars (ex. EVs) classified as "midsize" by the US EPA ranged from 12 to 56 mpgUS (20 to 4.2 L/100 km)[\[8\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-2019_epa_BestandWorst-9) However, due to environmental concerns caused by CO2 emissions, new EU regulations are being introduced to reduce the average emissions of cars sold beginning in 2012, to 130 g/km of CO2, equivalent to 4.5 L/100 km (52 mpgUS, 63 mpgimp) for a diesel-fueled car, and 5.0 L/100 km (47 mpgUS, 56 mpgimp) for a gasoline (petrol)-fueled car.[\[9\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-10)
The average consumption across the fleet is not immediately affected by the *new vehicle* fuel economy: for example, Australia's car fleet average in 2004 was 11.5 L/100 km (20.5 mpgUS),[\[10\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-11) compared with the average new car consumption in the same year of 9.3 L/100 km (25.3 mpgUS)[\[11\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-pew-12)
### Speed and fuel economy studies
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=3 "Edit section: Speed and fuel economy studies")\]
[](https://en.wikipedia.org/wiki/File:Fuel_economy_vs_speed_1997.png)
1997 fuel economy statistics for various US models
Fuel economy at steady speeds with selected vehicles was studied in 2010. The most recent study[\[12\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ornl-13) indicates greater fuel efficiency at higher speeds than earlier studies; for example, some vehicles achieve better fuel economy at 100 km/h (62 mph) rather than at 70 km/h (43 mph),[\[12\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ornl-13) although not their best economy, such as the 1994 [Oldsmobile Cutlass Ciera](https://en.wikipedia.org/wiki/Oldsmobile_Cutlass_Ciera "Oldsmobile Cutlass Ciera") with the [LN2](https://en.wikipedia.org/wiki/General_Motors_122_engine#LN2 "General Motors 122 engine") 2.2L engine, which has its best economy at 90 km/h (56 mph) (8.1 L/100 km (29 mpg‑US)), and gets better economy at 105 km/h (65 mph) than at 72 km/h (45 mph) (9.4 L/100 km (25 mpg‑US) vs 22 mpg‑US (11 L/100 km)). The proportion of driving on [high speed roadways](https://en.wikipedia.org/wiki/Highway_safety#Motorway "Highway safety") varies from 4% in Ireland to 41% in the Netherlands.
When the US [National Maximum Speed Law](https://en.wikipedia.org/wiki/National_Maximum_Speed_Law "National Maximum Speed Law")'s 55 mph (89 km/h) speed limit was mandated from 1974 to 1995, there were complaints that fuel economy could decrease instead of increase. The 1997 Toyota Celica got better fuel-efficiency at 105 km/h (65 mph) than it did at 65 km/h (40 mph) (5.41 L/100 km (43.5 mpg‑US) vs 5.53 L/100 km (42.5 mpg‑US)), although even better at 60 mph (97 km/h) than at 65 mph (105 km/h) (48.4 mpg‑US (4.86 L/100 km) vs 43.5 mpg‑US (5.41 L/100 km)), and its best economy (52.6 mpg‑US (4.47 L/100 km)) at only 25 mph (40 km/h). Other vehicles tested had from 1.4 to 20.2% better fuel-efficiency at 90 km/h (56 mph) vs. 105 km/h (65 mph). Their best economy was reached at speeds of 40 to 90 km/h (25 to 56 mph) (see graph).[\[12\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ornl-13)
Officials hoped that the 55 mph (89 km/h) limit, combined with a ban on ornamental lighting, no gasoline sales on Sunday, and a 15% cut in gasoline production, would reduce total gasoline consumption by 200,000 [barrels](https://en.wikipedia.org/wiki/Oil_barrel "Oil barrel") a day, representing a 2.2% drop from annualized 1973 gasoline consumption levels.[\[13\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-14)[\[b\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-16) This was partly based on a belief that cars achieve maximum efficiency between 40 and 50 mph (65 and 80 km/h) and that trucks and buses were most efficient at 55 mph (89 km/h).[\[15\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-17)
In 1998, the U.S. [Transportation Research Board](https://en.wikipedia.org/wiki/Transportation_Research_Board "Transportation Research Board") footnoted an estimate that the 1974 National Maximum Speed Limit (NMSL) reduced fuel consumption by 0.2 to 1.0 percent.[\[16\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-18) Rural interstates, the roads most visibly affected by the NMSL, accounted for 9.5% of the U.S' vehicle-miles-traveled in 1973,[\[17\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-19) but such free-flowing roads typically provide more fuel-efficient travel than conventional roads.[\[18\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-greenvehicleguide.gov.au-20) [\[19\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-lexus.de-21) [\[20\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-fueleconomy.gov-22)
### Discussion of statistics
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=4 "Edit section: Discussion of statistics")\]
A reasonably modern European [supermini](https://en.wikipedia.org/wiki/Supermini_car "Supermini car") and many mid-size cars, including station wagons, may manage [motorway](https://en.wikipedia.org/wiki/Motorway "Motorway") travel at 5 L/100 km (47 mpg‑US; 56 mpg‑imp) or 6.5 L/100 km (36 mpg‑US; 43 mpg‑imp), with [carbon dioxide](https://en.wikipedia.org/wiki/Carbon_dioxide "Carbon dioxide") emissions of around 140 g/km.
An average [North American](https://en.wikipedia.org/wiki/North_America "North America") [mid-size car](https://en.wikipedia.org/wiki/Mid-size_car "Mid-size car") averages 21 mpg‑US (11 L/100 km; 25 mpg‑imp)) city, 27 mpg‑US (8.7 L/100 km; 32 mpg‑imp)) highway; a [full-size](https://en.wikipedia.org/wiki/Full-size_car "Full-size car") [SUV](https://en.wikipedia.org/wiki/SUV "SUV") usually averages 13 mpg‑US (18 L/100 km; 16 mpg‑imp) city and 16 mpg‑US (15 L/100 km; 19 mpg‑imp) highway. [Pickup trucks](https://en.wikipedia.org/wiki/Pickup_truck "Pickup truck") vary considerably; whereas a 4 cylinder-engined light pickup can achieve 28 mpg‑US (8.4 L/100 km; 34 mpg‑imp), a [V8](https://en.wikipedia.org/wiki/V8_engine "V8 engine") full-size pickup with extended cabin averages13 mpg‑US (18 L/100 km; 16 mpg‑imp) city and 15 mpg‑US (16 L/100 km; 18 mpg‑imp) highway.
The average fuel economy for all vehicles on the road is higher in Europe than the United States because the higher cost of fuel changes [consumer behaviour](https://en.wikipedia.org/wiki/Consumer_behaviour "Consumer behaviour"). In the UK, an imperial gallon of fuel cost US\$6.06 in 2005. The average cost in the United States was US\$2.61 for a US gallon.[\[21\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-23)
European-built cars are generally more fuel-efficient than US vehicles. While Europe has many highly efficiency diesel cars, European gasoline/petrol vehicles are on average also more efficient than gasoline-powered vehicles in the USA. Most European vehicles cited in the CSI study run on diesel engines, which tend to achieve greater fuel efficiency than gasoline/petrol engines. Selling those cars in the United States is difficult because of emission standards, notes Walter McManus, a fuel economy expert at the University of Michigan Transportation Research Institute. "For the most part, European diesels don’t meet U.S. emission standards", McManus said in 2007. Another reason why many European models are not sold in the United States is that labor unions object to having the big 3 import any new foreign built models regardless of fuel economy while laying off workers at home.[\[22\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-24)
An example of European cars' capabilities of fuel economy is the [microcar](https://en.wikipedia.org/wiki/Microcar "Microcar") *[Smart Fortwo](https://en.wikipedia.org/wiki/Smart_Fortwo "Smart Fortwo")* cdi, which can achieve up to 3.4 L/100 km (83 mpg‑imp; 69 mpg‑US) using a [turbocharged](https://en.wikipedia.org/wiki/Turbocharger "Turbocharger") three-cylinder 30 kW (40 hp) Diesel engine. The Fortwo is produced by [Daimler AG](https://en.wikipedia.org/wiki/Daimler_AG "Daimler AG") and is only sold by one company in the United States. Furthermore, the world record in fuel economy of production cars is held by the [Volkswagen Group](https://en.wikipedia.org/wiki/Volkswagen_Group "Volkswagen Group"), with special production models (labeled "3L") of the [Volkswagen Lupo](https://en.wikipedia.org/wiki/Volkswagen_Lupo#Lupo_3L "Volkswagen Lupo") and the [Audi A2](https://en.wikipedia.org/wiki/Audi_A2#1.2_TDI_"3L" "Audi A2"), consuming as little as 3 L/100 km (94 mpg‑imp; 78 mpg‑US).[\[23\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-25)\[*[clarification needed](https://en.wikipedia.org/wiki/Wikipedia:Please_clarify "Wikipedia:Please clarify")*\]
[Diesel engines](https://en.wikipedia.org/wiki/Diesel_engine "Diesel engine") generally achieve greater fuel efficiency than petrol (gasoline) engines. Passenger car diesel engines have [energy efficiency](https://en.wikipedia.org/wiki/Energy_conversion_efficiency "Energy conversion efficiency") of up to 41% but more typically 30%, and petrol engines of up to 37.3%, but more typically 20%. A common margin is 25% more efficiency for a turbodiesel.
For example, the current model Skoda Octavia, using Volkswagen engines, has a combined European fuel efficiency of 5.7 L/100 km (50 mpg‑imp; 41 mpg‑US) for the 78 kW (105 hp) petrol engine and 4.5 L/100 km (63 mpg‑imp; 52 mpg‑US) for the 78 kW (105 hp) heavier diesel engine vehicle. The higher compression ratio raises the energy efficiency, but diesel fuel also contains approximately 10% more energy per unit volume than gasoline/petrol which contributes to the reduced fuel consumption for a given power output.
In 2002, the United States had 85,174,776 trucks, and averaged 13.5 mpg‑US (17.4 L/100 km; 16.2 mpg‑imp). Large trucks, over 33,000 lb (15,000 kg), averaged 5.7 mpg‑US (41 L/100 km; 6.8 mpg‑imp).[\[24\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-26)
| [GVWR](https://en.wikipedia.org/wiki/Gross_vehicle_weight_rating "Gross vehicle weight rating") lbs | Number | Percentage | Average miles per truck | fuel economy | Percentage of fuel use |
|---|---|---|---|---|---|
| 6,000 lbs and less | 51,941,389 | 61\.00% | 11,882 | 17\.6 | 42\.70% |
| 6,001 – 10,000 lbs | 28,041,234 | 32\.90% | 12,684 | 14\.3 | 30\.50% |
| Light truck subtotal | 79,982,623 | 93\.90% | 12,163 | 16\.2 | 73\.20% |
| 10,001 – 14,000 lbs | 691,342 | 0\.80% | 14,094 | 10\.5 | 1\.10% |
| 14,001 – 16,000 lbs | 290,980 | 0\.30% | 15,441 | 8\.5 | 0\.50% |
| 16,001 – 19,500 lbs | 166,472 | 0\.20% | 11,645 | 7\.9 | 0\.30% |
| 19,501 – 26,000 lbs | 1,709,574 | 2\.00% | 12,671 | 7 | 3\.20% |
| Medium truck subtotal | 2,858,368 | 3\.40% | 13,237 | 8 | 5\.20% |
| 26,001 – 33,000 lbs | 179,790 | 0\.20% | 30,708 | 6\.4 | 0\.90% |
| 33,001 lbs and up | 2,153,996 | 2\.50% | 45,739 | 5\.7 | 20\.70% |
| Heavy truck subtotal | 2,333,786 | 2\.70% | 44,581 | 5\.8 | 21\.60% |
| Total | 85,174,776 | 100\.00% | 13,088 | 13\.5 | 100\.00% |
The average economy of automobiles in the United States in 2002 was 22.0 miles per US gallon (10.7 L/100 km; 26.4 mpg‑imp). By 2010 this had increased to 23.0 miles per US gallon (10.2 L/100 km; 27.6 mpg‑imp). Average fuel economy in the United States gradually declined until 1973, when it reached a low of 13.4 miles per US gallon (17.6 L/100 km; 16.1 mpg‑imp) and gradually has increased since, as a result of higher fuel cost.[\[25\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-27) A study indicates that a 10% increase in gas prices will eventually produce a 2.04% increase in fuel economy.[\[26\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-28) One method by car makers to increase fuel efficiency is [lightweighting](https://en.wikipedia.org/wiki/Lightweighting "Lightweighting") in which lighter-weight materials are substituted in for improved engine performance and handling.[\[27\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-twsMercuryNews-29)
### Differences in testing standards
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=5 "Edit section: Differences in testing standards")\]
Identical vehicles can have varying fuel consumption figures listed depending upon the testing methods of the jurisdiction.[\[28\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-30)
Lexus [IS 250](https://en.wikipedia.org/wiki/Lexus_IS#Second_generation_\(2006%E2%80%93present\) "Lexus IS") – petrol 2.5 L *[4GR-FSE](https://en.wikipedia.org/wiki/Toyota_GR_engine#4GR-FSE "Toyota GR engine")* [V6](https://en.wikipedia.org/wiki/V6 "V6"), 204 hp (153 kW), 6 speed automatic, rear wheel drive
- **Australia** (L/100 km) – 'combined' 9.1, 'urban' 12.7, 'extra-urban' 7.0[\[18\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-greenvehicleguide.gov.au-20)
- **Canada** (L/100 km) – 'combined' 9.6, 'city' 11.1, 'highway' 7.8[\[29\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-31)
- **European Union** (L/100 km) – 'combined' 8.9, 'urban' 12.5, 'extra-urban' 6.9[\[19\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-lexus.de-21)
- **United States** (L/100 km) – 'combined' 9.8, 'city' 11.2, 'highway' 8.1[\[20\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-fueleconomy.gov-22)
## Energy considerations
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=6 "Edit section: Energy considerations")\]
| | |
|---|---|
| [](https://en.wikipedia.org/wiki/File:Question_book-new.svg) | This section **needs additional citations for [verification](https://en.wikipedia.org/wiki/Wikipedia:Verifiability "Wikipedia:Verifiability")**. Please help [improve this article](https://en.wikipedia.org/wiki/Special:EditPage/Fuel_economy_in_automobiles "Special:EditPage/Fuel economy in automobiles") by [adding citations to reliable sources](https://en.wikipedia.org/wiki/Help:Referencing_for_beginners "Help:Referencing for beginners") in this section. Unsourced material may be challenged and removed. *Find sources:* ["Fuel economy in automobiles"](https://www.google.com/search?as_eq=wikipedia&q=%22Fuel+economy+in+automobiles%22) – [news](https://www.google.com/search?tbm=nws&q=%22Fuel+economy+in+automobiles%22+-wikipedia&tbs=ar:1) **·** [newspapers](https://www.google.com/search?&q=%22Fuel+economy+in+automobiles%22&tbs=bkt:s&tbm=bks) **·** [books](https://www.google.com/search?tbs=bks:1&q=%22Fuel+economy+in+automobiles%22+-wikipedia) **·** [scholar](https://scholar.google.com/scholar?q=%22Fuel+economy+in+automobiles%22) **·** [JSTOR](https://www.jstor.org/action/doBasicSearch?Query=%22Fuel+economy+in+automobiles%22&acc=on&wc=on) *(November 2023)* *([Learn how and when to remove this message](https://en.wikipedia.org/wiki/Help:Maintenance_template_removal "Help:Maintenance template removal"))* |
Since the total force opposing the vehicle's motion (at constant speed) multiplied by the distance through which the vehicle travels represents the work that the vehicle's engine must perform, the study of fuel economy (the amount of energy consumed per unit of distance traveled) requires a detailed analysis of the forces that oppose a vehicle's motion. In terms of physics, Force = rate at which the amount of work generated (energy delivered) varies with the distance traveled, or:
F
\=
d
W
d
s
∝
Fuel economy
{\\displaystyle F={\\frac {dW}{ds}}\\propto {\\text{Fuel economy}}}
Note: The amount of work generated by the vehicle's power source (energy delivered by the engine) would be exactly proportional to the amount of fuel energy consumed by the engine if the engine's efficiency is the same regardless of power output, but this is not necessarily the case due to the operating characteristics of the internal combustion engine.
For a vehicle whose source of power is a heat engine (an engine that uses heat to perform useful work), the amount of fuel energy that a vehicle consumes per unit of distance (level road) depends upon:
1. The [thermodynamic efficiency of the heat engine](https://en.wikipedia.org/wiki/Energy_efficiency_of_internal_combustion_engines "Energy efficiency of internal combustion engines");
2. Frictional losses within the [drivetrain](https://en.wikipedia.org/wiki/Drivetrain "Drivetrain");
3. [Rolling resistance](https://en.wikipedia.org/wiki/Rolling_resistance "Rolling resistance") within the wheels and between the road and the wheels;
4. Non-motive subsystems powered by the engine, such as [air conditioning](https://en.wikipedia.org/wiki/Automobile_air_conditioning "Automobile air conditioning"), [engine cooling](https://en.wikipedia.org/wiki/Internal_combustion_engine_cooling "Internal combustion engine cooling"), and the [alternator](https://en.wikipedia.org/wiki/Alternator_\(automotive\) "Alternator (automotive)");
5. [Aerodynamic drag](https://en.wikipedia.org/wiki/Drag_\(physics\) "Drag (physics)") from moving through air;
6. Energy converted by [frictional brakes](https://en.wikipedia.org/wiki/Friction_brake "Friction brake") into waste heat, or losses from [regenerative braking](https://en.wikipedia.org/wiki/Regenerative_brake "Regenerative brake") in [hybrid vehicles](https://en.wikipedia.org/wiki/Hybrid_vehicle "Hybrid vehicle");
7. Fuel consumed while the engine is not providing power but still running, such as while [idling](https://en.wikipedia.org/wiki/Idle_\(engine\) "Idle (engine)"), minus the subsystem loads.[\[30\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-32)
[](https://en.wikipedia.org/wiki/File:Energy_flows_in_car.svg)
Energy dissipation in city and highway driving for a mid-size gasoline-powered car
Ideally, a car traveling at a constant velocity on level ground in a vacuum with frictionless wheels could travel at any speed without consuming any energy beyond what is needed to get the car up to speed. Less ideally, any vehicle must expend energy on overcoming road load forces, which consist of aerodynamic drag, tire rolling resistance, and inertial energy that is lost when the vehicle is decelerated by friction brakes. With ideal [regenerative braking](https://en.wikipedia.org/wiki/Regenerative_braking "Regenerative braking"), the inertial energy could be completely recovered, the only options for reducing aerodynamic drag or rolling resistance other than optimizing the vehicle's shape and the tire design. Road load energy or the energy demanded at the wheels, can be calculated by evaluating the vehicle equation of motion over a specific driving cycle.[\[31\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-33) The vehicle powertrain must then provide this minimum energy to move the vehicle and will lose a large amount of additional energy in the process of converting fuel energy into work and transmitting it to the wheels. Overall, the sources of energy loss in moving a vehicle may be summarized as follows:
- [Engine efficiency](https://en.wikipedia.org/wiki/Engine_efficiency "Engine efficiency") (20–30%), which varies with engine type, the mass of the automobile and its load, and engine speed (usually measured in [RPM](https://en.wikipedia.org/wiki/Revolutions_per_minute "Revolutions per minute")).
- [Aerodynamic drag](https://en.wikipedia.org/wiki/Aerodynamic_drag "Aerodynamic drag") force, which increases roughly by the [square of the car's speed](https://en.wikipedia.org/wiki/Drag_equation "Drag equation"), but notes that [drag power goes by the cube of the car's speed](https://en.wikipedia.org/wiki/Drag_power "Drag power").
- [Rolling friction](https://en.wikipedia.org/wiki/Rolling_friction "Rolling friction").
- Braking, although [regenerative braking](https://en.wikipedia.org/wiki/Regenerative_braking "Regenerative braking") captures some of the energy that would otherwise be lost.
- Losses in the [transmission](https://en.wikipedia.org/wiki/Transmission_\(mechanics\) "Transmission (mechanics)"). [Manual transmissions](https://en.wikipedia.org/wiki/Manual_transmission "Manual transmission") can be up to 94% efficient whereas older [automatic transmissions](https://en.wikipedia.org/wiki/Automatic_transmission "Automatic transmission") may be as low as 70% efficient[\[32\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-34) [Automated manual transmissions](https://en.wikipedia.org/wiki/Automated_manual_transmission "Automated manual transmission"), which have the same mechanical internals as conventional [manual transmissions](https://en.wikipedia.org/wiki/Manual_transmission "Manual transmission"), will give the same efficiency as a pure manual gearbox plus the added bonus of intelligence selecting optimal shifting points, and/or automated clutch control but manual shifting, as with older [semi-automatic transmissions](https://en.wikipedia.org/wiki/Semi-automatic_transmission "Semi-automatic transmission").
- Air conditioning. The power required for the engine to turn the compressor decreases the fuel-efficiency, though only when in use. This may be offset by the reduced drag of the vehicle compared with driving with the windows down. The efficiency of AC systems gradually deteriorates due to dirty filters etc.; regular maintenance prevents this. The extra mass of the air conditioning system will cause a slight increase in fuel consumption.
- Power steering. The older hydraulic power steering systems are powered by a hydraulic pump constantly engaged to the engine. Power assistance required for steering is inversely proportional to the vehicle speed so the constant load on the engine from a hydraulic pump reduces fuel efficiency. More modern designs improve fuel efficiency by only activating the power assistance when needed; this is done by using either direct electrical power steering assistance or an electrically powered hydraulic pump.
- Cooling. The older cooling systems used a constantly engaged mechanical fan to draw air through the radiator at a rate directly related to the engine speed. This constant load reduces efficiency. More modern systems use electrical fans to draw additional air through the radiator when extra cooling is required.
- Electrical systems. Headlights, battery charging, active suspension, circulating fans, defrosters, media systems, speakers, and other electronics can also significantly increase fuel consumption, as the energy to power these devices causes an increased load on the alternator. Since alternators are commonly only 40–60% efficient, the added load from electronics on the engine can be as high as 3 horsepower (2.2 kW) at any speed including idle. In the FTP 75 cycle test, a 200-watt load on the alternator reduces fuel efficiency by 1.7 mpg‑US (140 L/100 km; 2.0 mpg‑imp).[\[33\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ieee-35) Headlights, for example, consume 110 watts on low and up to 240 watts on high. These electrical loads can cause much of the discrepancy between real-world and EPA tests, which only include the electrical loads required to run the engine and basic climate control.
- Standby. The energy is needed to keep the engine running while it is not providing power to the wheels, i.e., when stopped, coasting or braking.
Fuel-efficiency decreases from electrical loads are most pronounced at lower speeds because most electrical loads are constant while engine load increases with speed. So at a lower speed, a higher proportion of [engine power](https://en.wikipedia.org/wiki/Engine_power "Engine power") is used by electrical loads. Hybrid cars see the greatest effect on fuel-efficiency from electrical loads because of this proportional effect.
### Fuel economy-boosting technologies
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=7 "Edit section: Fuel economy-boosting technologies")\]
Main article: [Fuel saving devices](https://en.wikipedia.org/wiki/Fuel_saving_devices "Fuel saving devices")
#### Engine-specific technology
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=8 "Edit section: Engine-specific technology")\]
| Type | Technology | Explanation | Inventor | Notes |
|---|---|---|---|---|
| Engine cycle | Replacing petrol engines with diesel engines | Reduces brake specific fuel consumption at lower RPM | Herbert Akroyd Stuart | |
| Engine combustion strategies | Electronic control of the cooling system | Optimizes engine running temperature | | |
| | Stratified Charge combustion | Injects fuel into cylinder just before ignition, increasing compression ratio | | For use in petrol engines |
| | Lean burn combustion | Increases air/fuel ratio to reduce throttling losses | Chrysler | <https://www.youtube.com/watch?v=KnNX6gtDyhg> |
| | Cooled [exhaust gas recirculation](https://en.wikipedia.org/wiki/Exhaust_gas_recirculation "Exhaust gas recirculation") (petrol) | Reduces throttling losses, heat rejection, chemical dissociation, and specific heat ratio | | |
| | Cooled exhaust gas recirculation (diesel) | Lowers peak combustion temperatures | | |
| | [Atkinson cycle](https://en.wikipedia.org/wiki/Atkinson_cycle "Atkinson cycle") | Lengthens power stroke to achieve greater thermal efficiency | James Atkinson | [](https://en.wikipedia.org/wiki/File:Atkinson_Gas_Engine_Animated.gif) Atkinson cycle |
| | [Variable valve timing](https://en.wikipedia.org/wiki/Variable_valve_timing "Variable valve timing") and [variable valve lift](https://en.wikipedia.org/wiki/Variable_valve_lift "Variable valve lift") | Alters valve lift timing and height for precise control over intake and exhaust | | William Howe and William Williams ([Robert Stephenson and Company](https://en.wikipedia.org/wiki/Robert_Stephenson_and_Company "Robert Stephenson and Company")) invented the first [variable timing valve](https://en.wikipedia.org/wiki/Stephenson_valve_gear "Stephenson valve gear") |
| | Variable geometry turbocharging | Optimizes airflow with adjustable vanes to regulate turbocharger's air intake and eliminate turbo lag | Garrett ([Honeywell](https://en.wikipedia.org/wiki/Honeywell_Turbo_Technologies "Honeywell Turbo Technologies")) | [](https://en.wikipedia.org/wiki/File:VNT_Vanes_Open.jpg) VNT Vanes Open |
| | Twincharging | Combines a supercharger with a turbocharger to eliminate turbo lag | Lancia | For use in small-displacement engines |
| | Gasoline direct injection (GDI) engines | Allows for stratified fuel charge and ultra-lean burn | Leon Levavasseur | |
| | [Turbocharged Direct Injection](https://en.wikipedia.org/wiki/Turbocharged_Direct_Injection "Turbocharged Direct Injection") diesel engines | Combines direct injection with a turbocharger | Volkswagen | |
| | Common rail direct injection | Increases injection pressure | Robert Huber | |
| | Piezoelectric diesel injectors | Uses multiple injections per engine cycle for increased precision | | |
| | Cylinder management | Shuts off individual cylinders when their power output is not needed | | |
| | HCCI (Homogeneous Charge Compression Ignition) combustion | Allows leaner and higher compression burn | | <https://www.youtube.com/watch?v=B8CnYljXAS0> |
| | [Scuderi engine](https://en.wikipedia.org/wiki/Scuderi_engine "Scuderi engine") | Eliminates recompression losses | Carmelo J. Scuderi | [](https://en.wikipedia.org/wiki/File:Scuderi_Split_Cycle_Engine_-_Cycle.gif) Scuderi engine |
| | Compound engines (6-stroke engine or turbo-compound engine) | Recovers exhaust energy | | |
| | Two-stroke diesel engines | Increases power to weight ratio | Charles F. Kettering | |
| | High-efficiency gas turbine engines | Increases power to weight ratio | | |
| | Turbosteamer | Uses heat from the engine to spin a mini turbine to generate power | Raymond Freymann (BMW) | |
| | Stirling hybrid battery vehicle | Increases thermal efficiency | Still largely theoretical, although prototypes have been produced by Dean Kamen | |
| | Time-optimized piston path | Captures energy from gases in the cylinders at their highest temperatures | | |
| Engine internal losses | Downsized engines with a supercharger or a turbocharger | Reduces engine displacement while maintaining sufficient torque | Saab, starting with the 99 in 1978. | [](https://en.wikipedia.org/wiki/File:2014-Global-Turbo-Forecast.png) 2014-Global-Turbo-Forecast |
| | Lower-friction lubricants (engine oil, transmission fluid, axle fluid) | Reduces energy lost to friction | | |
| | Lower viscosity engine oils | Reduces hydrodynamic friction and energy required to circulate | | |
| | Variable displacement oil pump | Avoids excessive flow rate at high engine speed | | |
| | Electrifying engine accessories (water pump, power steering pump, and air conditioner compressor) | Sends more engine power to the transmission or reduces the fuel required for the same traction power | | |
| | Roller type cam, low friction coating on piston skirt and optimizing load-bearing surface, e.g. camshaft bearing and connective rods. | Reduces engine frictions | | |
| Engine running conditions | Coolant additives | Increases the thermal efficiency of the cooling system | | |
| | Increasing the number of gearbox ratios in manual gearboxes | Lowers the engine rpm at cruise | | |
| | Reducing the volume of water-based cooling systems | Engine reaches its efficient operating temperature more quickly | | |
| | [Start-stop system](https://en.wikipedia.org/wiki/Start-stop_system "Start-stop system") | Automatically shuts off engine when vehicle is stopped, reducing idle time | | |
| | Downsized engines with an electric drive system and battery | Avoids low-efficiency idle and power conditions | | |
#### Other vehicle technologies
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=9 "Edit section: Other vehicle technologies")\]
| Type | Technology | Explanation | Inventor | Notes |
|---|---|---|---|---|
| Transmission losses | Continuously variable transmission (CVT) | Enables engine to run at its most efficient RPM | | For use in automatic gearboxes |
| | Locking torque converters in automatic transmissions | Reduces slip and power losses in the converter | | |
| Rolling resistance | Lighter construction materials (aluminum, fiberglass, plastic, high-strength steel, and carbon fiber) | Reduces vehicle weight | | |
| | Increasing tire pressure | Lowers tire deformation under weight | | |
| | Replacing tires with low rolling resistance (LRR) models | Lowers rolling resistance[\[34\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-36) | | |
| Series parallel hybrid | Using an electric motor for the base power and an IC engine for assists and boosts, when needed | Decreases fuel consumption by running the petrol engine only when needed, in this way also environmentally friendly. | TRW | |
| Energy saving | Lighter materials for moving parts (pistons, crankshaft, gears, and alloy wheels) | Reduces the energy required to move parts | | |
| | [Regenerative braking](https://en.wikipedia.org/wiki/Regenerative_braking "Regenerative braking") | Captures kinetic energy while braking | Louis Antoine Kriéger | For use in hybrid or electric vehicles |
| | Recapturing waste heat from the exhaust system | Converts heat energy into electricity using [thermoelectric cooling](https://en.wikipedia.org/wiki/Thermoelectric_cooling "Thermoelectric cooling") | [Jean Charles Athanase Peltier](https://en.wikipedia.org/wiki/Jean_Charles_Athanase_Peltier "Jean Charles Athanase Peltier") | |
| | Regenerative shock absorbers | Recaptures wasted energy in the vehicle suspension[\[35\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-37) | Levant Power | |
| Traffic management | Active highway management | Matches speed limits and vehicles allowed to join motorways with traffic density to maintain traffic throughput | | |
| | Vehicle electronic control systems that automatically maintain distances between vehicles on motorways | Reduces ripple back braking and consequent re-acceleration | | |
#### Future technologies
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=10 "Edit section: Future technologies")\]
Technologies that may improve fuel efficiency, but are not yet on the market, include:
- [HCCI](https://en.wikipedia.org/wiki/HCCI "HCCI") (Homogeneous Charge Compression Ignition) combustion
- [Scuderi engine](https://en.wikipedia.org/wiki/Scuderi_engine "Scuderi engine")
- [Compound engines](https://en.wikipedia.org/wiki/Compound_engine "Compound engine")
- [Two-stroke diesel engines](https://en.wikipedia.org/wiki/Two-stroke_diesel_engine "Two-stroke diesel engine")
- High-efficiency [gas turbine engines](https://en.wikipedia.org/wiki/Gas_turbine_engine "Gas turbine engine")
- BMW's [Turbosteamer](https://en.wikipedia.org/wiki/Turbosteamer "Turbosteamer") – using the heat from the engine to spin a mini turbine to generate power
- Vehicle electronic control systems that automatically maintain distances between vehicles on motorways/freeways that reduce *ripple back braking*, and consequent re-acceleration.
- Time-optimized piston path, to capture energy from hot gases in the cylinders when they are at their highest temperatures\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\]
- sterling hybrid battery vehicle
Many [aftermarket consumer products](https://en.wikipedia.org/wiki/Aftermarket_fuel_economy_device "Aftermarket fuel economy device") exist that are purported to increase fuel economy; many of these claims have been discredited. In the United States, the Environmental Protection Agency maintains a list of devices that have been tested by independent laboratories and makes the test results available to the public.[\[36\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-38)
### Fuel economy maximizing behaviors
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=11 "Edit section: Fuel economy maximizing behaviors")\]
Main article: [Fuel economy-maximizing behaviors](https://en.wikipedia.org/wiki/Fuel_economy-maximizing_behaviors "Fuel economy-maximizing behaviors")
Governments, various environmentalist organizations, and companies like [Toyota](https://en.wikipedia.org/wiki/Toyota "Toyota") and [Shell Oil Company](https://en.wikipedia.org/wiki/Shell_Oil_Company "Shell Oil Company") have historically urged drivers to maintain adequate air pressure in [tires](https://en.wikipedia.org/wiki/Tire "Tire") and careful acceleration/deceleration habits. Keeping track of fuel efficiency stimulates fuel economy-maximizing behavior.[\[37\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-39)
A five-year partnership between [Michelin](https://en.wikipedia.org/wiki/Michelin "Michelin") and [Anglian Water](https://en.wikipedia.org/wiki/Anglian_Water "Anglian Water") shows that 60,000 liters of fuel can be saved on tire pressure. The Anglian Water fleet of 4,000 vans and cars are now lasting their full lifetime. This shows the impact that tire pressures have on the fuel efficiency.[\[38\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-40)
### Fuel economy as part of quality management regimes
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=12 "Edit section: Fuel economy as part of quality management regimes")\]
[Environmental management](https://en.wikipedia.org/wiki/Environmental_management "Environmental management") systems [EMAS](https://en.wikipedia.org/wiki/Eco-Management_and_Audit_Scheme "Eco-Management and Audit Scheme"), as well as good fleet management, includes record-keeping of the fleet fuel consumption. Quality management uses those figures to steer the measures acting on the fleets. This is a way to check whether procurement, driving, and maintenance in total have contributed to changes in the fleet's overall consumption.
## Fuel economy standards and testing procedures
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=13 "Edit section: Fuel economy standards and testing procedures")\]
| Country | 2004 average | Requirement | | | |
|---|---|---|---|---|---|
| 2004 | 2005 | 2008 | Later | | |
| People's Republic of China[\[39\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-41) | | | 6\.9 L/100 km | 6\.9 L/100 km | 6\.1 L/100 km |
| [United States](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#United_States) | 24\.6 mpg (9.5 L/100 km) (cars and trucks)\* | 27 mpg (8.7 L/100 km) (cars only)\* | | | 35 mpg (6.7 L/100 km) (Model Year 2020, cars & light trucks) |
| [European Union](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Europe) | | | | | 4\.1 L/100 km (2020, [NEDC](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Europe)) |
| [Japan](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Japan)[\[11\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-pew-12) | | | | | 6\.7 L/100 km [CAFE](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#CAFE_standards) eq (2010) |
| [Australia](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Australia)[\[11\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-pew-12) | 8\.08 L/100 km CAFE eq (2002) | none | | | none (as of March 2019)[\[40\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-42) |
\* highway \*\* combined
### Australia
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=14 "Edit section: Australia")\]
From October 2008, all new cars had to be sold with a sticker on the windscreen showing the fuel consumption and the CO2 emissions.[\[41\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-43) Fuel consumption figures are expressed as *urban*, *extra urban* and *combined*, measured according to [ECE Regulations](https://en.wikipedia.org/wiki/ECE_Regulations "ECE Regulations") 83 and 101 – which are the based on the [European driving cycle](https://en.wikipedia.org/wiki/New_European_Driving_Cycle "New European Driving Cycle"); previously, only the *combined* number was given.
Australia also uses a star rating system, from one to five stars, that combines greenhouse gases with pollution, rating each from 0 to 10 with ten being best. To get 5 stars a combined score of 16 or better is needed, so a car with a 10 for economy (greenhouse) and a 6 for emission or 6 for economy and 10 for emission, or anything in between would get the highest 5 star rating.[\[42\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-44) The lowest rated car is the [Ssangyong Korrando](https://en.wikipedia.org/wiki/SsangYong_Korando "SsangYong Korando") with automatic transmission, with one star, while the highest rated was the Toyota Prius hybrid. The Fiat 500, Fiat Punto and Fiat Ritmo as well as the Citroen C3 also received 5 stars.[\[43\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-45) The greenhouse rating depends on the fuel economy and the type of fuel used. A greenhouse rating of 10 requires 60 or less grams of CO2 per km, while a rating of zero is more than 440 g/km CO2. The highest greenhouse rating of any 2009 car listed is the Toyota Prius, with 106 g/km CO2 and 4.4 L/100 km (64 mpg‑imp; 53 mpg‑US). Several other cars also received the same rating of 8.5 for greenhouse. The lowest rated was the Ferrari 575 at 499 g/km CO2 and 21.8 L/100 km (13.0 mpg‑imp; 10.8 mpg‑US). The Bentley also received a zero rating, at 465 g/km CO2. The best fuel economy of any year is the 2004–2005 [Honda Insight](https://en.wikipedia.org/wiki/Honda_Insight "Honda Insight"), at 3.4 L/100 km (83 mpg‑imp; 69 mpg‑US).
### Canada
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=15 "Edit section: Canada")\]
Vehicle manufacturers follow a controlled laboratory testing procedure to generate the fuel consumption data that they submit to the Government of Canada. This controlled method of fuel consumption testing, including the use of standardized fuels, test cycles and calculations, is used instead of on-road driving to ensure that all vehicles are tested under identical conditions and that the results are consistent and repeatable.
Selected test vehicles are "run in" for about 6,000 km before testing. The vehicle is then mounted on a chassis dynamometer programmed to take into account the aerodynamic efficiency, weight and rolling resistance of the vehicle. A trained driver runs the vehicle through standardized driving cycles that simulate trips in the city and on the highway. Fuel consumption ratings are derived from the emissions generated during the driving cycles.[\[44\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-nrcan.gc.ca-46)
THE 5 CYCLE TEST:
1. The **city test** simulates urban driving in stop-and-go traffic with an average speed of 34 km/h and a top speed of 90 km/h. The test runs for approximately 31 minutes and includes 23 stops. The test begins from a cold engine start, which is similar to starting a vehicle after it has been parked overnight during the summer. The final phase of the test repeats the first eight minutes of the cycle but with a hot engine start. This simulates restarting a vehicle after it has been warmed up, driven and then stopped for a short time. Over five minutes of test time are spent idling, to represent waiting at traffic lights. The ambient temperature of the test cell starts at 20 °C and ends at 30 °C.
2. The **highway test** simulates a mixture of open highway and rural road driving, with an average speed of 78 km/h and a top speed of 97 km/h. The test runs for approximately 13 minutes and does not include any stops. The test begins from a hot engine start. The ambient temperature of the test cell starts at 20 °C and ends at 30 °C.
3. In the **cold temperature operation test**, the same driving cycle is used as in the standard **city test**, except that the ambient temperature of the test cell is set to −7 °C.
4. In the **air conditioning test**, the ambient temperature of the test cell is raised to 35 °C. The vehicle's climate control system is then used to lower the internal cabin temperature. Starting with a warm engine, the test averages 35 km/h and reaches a maximum speed of 88 km/h. Five stops are included, with idling occurring 19% of the time.
5. The **high speed/quick acceleration test** averages 78 km/h and reaches a top speed of 129 km/h. Four stops are included and brisk acceleration maximizes at a rate of 13.6 km/h per second. The engine begins warm and air conditioning is not used. The ambient temperature of the test cell is constantly 25 °C.
Tests 1, 3, 4, and 5 are averaged to create the city driving fuel consumption rate.
Tests 2, 4, and 5 are averaged to create the highway driving fuel consumption rate.[\[44\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-nrcan.gc.ca-46)
### Europe
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=16 "Edit section: Europe")\]
[](https://en.wikipedia.org/wiki/File:Irish_Car_CO2_Label.svg)
Irish fuel economy label
Main article: [New European Driving Cycle](https://en.wikipedia.org/wiki/New_European_Driving_Cycle "New European Driving Cycle")
| | |
|---|---|
|  | This section's **[factual accuracy](https://en.wikipedia.org/wiki/Wikipedia:Accuracy_dispute "Wikipedia:Accuracy dispute") may be compromised due to out-of-date information**. The reason given is: **[Worldwide harmonized Light vehicles Test Procedure](https://en.wikipedia.org/wiki/Worldwide_harmonized_Light_vehicles_Test_Procedure "Worldwide harmonized Light vehicles Test Procedure") WLTP replaced NEDC for vehicles certified after September 2018**. Please help update this article to reflect recent events or newly available information. *(September 2018)* |
In the European Union, passenger vehicles are commonly tested using two drive cycles, and corresponding fuel economies are reported as "urban" and "extra-urban", in liters per 100 km and (in the UK) in miles per imperial gallon.
The urban economy is measured using the test cycle known as ECE-15, first introduced in 1970 by EC Directive 70/220/EWG and finalized by EEC Directive 90/C81/01 in 1999. It simulates a 4,052 m (2.518 mile) urban trip at an average speed of 18.7 km/h (11.6 mph) and at a maximum speed of 50 km/h (31 mph).
The extra-urban driving cycle or EUDC lasts 400 seconds (6 minutes 40 seconds) at an average speed 62.6 km/h (39 mph) and a top speed of 120 km/h (74.6 mph).[\[45\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-47)
EU fuel consumption numbers are often considerably lower than corresponding US EPA test results for the same vehicle. For example, the 2011 [Honda CR-Z](https://en.wikipedia.org/wiki/Honda_CR-Z "Honda CR-Z") with a six-speed manual transmission is rated 6.1/4.4 L/100 km in Europe[\[46\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-48) and 7.6/6.4 L/100 km (31/37 mpg ) in the United States.[\[47\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-49)
In the European Union advertising has to show [carbon dioxide](https://en.wikipedia.org/wiki/Carbon_dioxide "Carbon dioxide") (CO2)-emission and fuel consumption data in a clear way as described in the UK Statutory Instrument 2004 No 1661.[\[48\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-50) Since September 2005 a color-coded "Green Rating" sticker has been available in the UK, which rates fuel economy by CO2 emissions: A: \<= 100 g/km, B: 100–120, C: 121–150, D: 151–165, E: 166–185, F: 186–225, and G: 226+. Depending on the type of fuel used, for gasoline A corresponds to about 4.1 L/100 km (69 mpg‑imp; 57 mpg‑US) and G about 9.5 L/100 km (30 mpg‑imp; 25 mpg‑US).[\[49\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-51) Ireland has a very similar label, but the ranges are slightly different, with A: \<= 120 g/km, B: 121–140, C: 141–155, D: 156–170, E: 171–190, F: 191–225, and G: 226+.[\[50\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-52) From 2020, EU requires manufacturers to average 95 g/km CO2 emission or less, or pay an [excess emissions premium](https://en.wikipedia.org/wiki/Fine_\(penalty\) "Fine (penalty)").[\[51\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-53)
In the UK the ASA (Advertising standards agency) have claimed that fuel consumption figures are misleading. Often the case with European vehicles as the MPG (miles per gallon) figures that can be advertised are often not the same as "real world" driving.
The ASA have said that car manufacturers can use "cheats" to prepare their vehicles for their compulsory fuel efficiency and emissions tests in a way set out to make themselves look as "clean" as possible. This practice is common in gasoline and diesel vehicle tests, but hybrid and electric vehicles are not immune as manufacturers apply these techniques to fuel efficiency.
Car experts\[*[who?](https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style/Words_to_watch#Unsupported_attributions "Wikipedia:Manual of Style/Words to watch")*\] also assert that the *official* MPG figures given by manufacturers do not represent the *true* MPG values from real-world driving.[\[52\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-54) Websites have been set up to show the real-world MPG figures, based on crowd-sourced data from real users, vs the official MPG figures.[\[53\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-55)
The major loopholes in the current EU tests allow car manufacturers a number of "cheats" to improve results. Car manufacturers can:
- Disconnect the alternator, thus no energy is used to recharge the battery;
- Use special lubricants that are not used in production cars, in order to reduce friction;
- Turn off all electrical gadgets i.e. Air Con/Radio;
- Adjust brakes or even disconnect them to reduce friction;
- Tape up cracks between body panels and windows to reduce air resistance;
- Remove Wing mirrors.[\[54\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-56)
According to the results of a 2014 study by the [International Council on Clean Transportation](https://en.wikipedia.org/wiki/International_Council_on_Clean_Transportation "International Council on Clean Transportation") (ICCT), the gap between official and real-world fuel-economy figures in Europe has risen to about 38% in 2013 from 10% in 2001. The analysis found that for private cars, the difference between on-road and official CO2 values rose from around 8% in 2001 to 31% in 2013, and 45% for company cars in 2013. The report is based on data from more than half a million private and company vehicles across Europe. The analysis was prepared by the ICCT together with the [Netherlands Organization for Applied Scientific Research](https://en.wikipedia.org/wiki/Netherlands_Organization_for_Applied_Scientific_Research "Netherlands Organization for Applied Scientific Research") (TNO), and the German Institut für Energie- und Umweltforschung Heidelberg (IFEU).[\[55\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-57)
In 2018 update of the ICCT data the difference between the official and real figures was again 38%.[\[56\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-58)
### Japan
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=17 "Edit section: Japan")\]
The evaluation criteria used in Japan reflects driving conditions commonly found, as the typical Japanese driver does not drive as fast as other regions internationally ([Speed limits in Japan](https://en.wikipedia.org/wiki/Speed_limits_in_Japan "Speed limits in Japan")).
#### 10–15 mode
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=18 "Edit section: 10–15 mode")\]
The 10–15 mode [driving cycle](https://en.wikipedia.org/wiki/Driving_cycle "Driving cycle") test is the official fuel economy and emission certification test for new light duty vehicles in Japan. Fuel economy is expressed in km/L (kilometers per liter) and emissions are expressed in g/km. The test is carried out on a [dynamometer](https://en.wikipedia.org/wiki/Dynamometer "Dynamometer") and consist of 25 tests which cover idling, acceleration, steady running and deceleration, and simulate typical Japanese urban and/or expressway driving conditions. The running pattern begins with a warm start, lasts for 660 seconds (11 minutes) and runs at speeds up to 70 km/h (43.5 mph).[\[57\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-JapTest01-59)[\[58\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-JapTest02-60) The distance of the cycle is 6.34 km (3.9 mi), average speed of 25.6 km/h (15.9 mph), and duration 892 seconds (14.9 minutes), including the initial 15 mode segment.[\[58\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-JapTest02-60)
#### JC08
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=19 "Edit section: JC08")\]
A new more demanding test, called the JC08, was established in December 2006 for Japan's new standard that goes into effect in 2015, but it is already being used by several car manufacturers for new cars. The JC08 test is significantly longer and more rigorous than the 10–15 mode test. The running pattern with JC08 stretches out to 1200 seconds (20 minutes), and there are both cold and warm start measurements and top speed is 82 km/h (51.0 mph). The economy ratings of the JC08 are lower than the 10–15 mode cycle, but they are expected to be more real world.[\[57\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-JapTest01-59) The [Toyota Prius](https://en.wikipedia.org/wiki/Toyota_Prius "Toyota Prius") became the first car to meet Japan's new 2015 Fuel Economy Standards measured under the JC08 test.[\[59\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-61)
### New Zealand
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=20 "Edit section: New Zealand")\]
Starting on 7 April 2008, all cars of up to 3.5 tonnes GVW sold other than private sale need to have a fuel economy sticker applied (if available) that shows the rating from one half star to six stars with the most economic cars having the most stars and the more fuel hungry cars the least, along with the fuel economy in L/100 km and the estimated annual fuel cost for driving 14,000 km (at present fuel prices). The stickers must also appear on vehicles to be leased for more than 4 months. All new cars currently rated range from 6.9 L/100 km (41 mpg‑imp; 34 mpg‑US) to 3.8 L/100 km (74 mpg‑imp; 62 mpg‑US) and received respectively from 4.5 to 5.5 stars.[\[60\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-62)
### Saudi Arabia
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=21 "Edit section: Saudi Arabia")\]
The [Kingdom of Saudi Arabia](https://en.wikipedia.org/wiki/Kingdom_of_Saudi_Arabia "Kingdom of Saudi Arabia") announced new light-duty vehicle fuel economy standards in November 2014 which became effective 1 January 2016 and will be fully phased in by 1 January 2018 ([Saudi Standards](https://en.wikipedia.org/wiki/Saudi_Standards,_Metrology_and_Quality_Organization "Saudi Standards, Metrology and Quality Organization") regulation SASO-2864). A review of the targets will be carried by December 2018, at which time targets for 2021–2025 will be set.
### United States
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=22 "Edit section: United States")\]
[](https://en.wikipedia.org/wiki/File:Motor_vehicle_efficiency.png)
Motor vehicle fuel economy from 1949 to 2021
#### US Energy Tax Act
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=23 "Edit section: US Energy Tax Act")\]
Main article: [Energy Tax Act](https://en.wikipedia.org/wiki/Energy_Tax_Act "Energy Tax Act")
The [Energy Tax Act](https://en.wikipedia.org/wiki/Energy_Tax_Act "Energy Tax Act") of 1978[\[61\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-63) in the US established a gas guzzler tax on the sale of new model year vehicles whose fuel economy fails to meet certain statutory levels. The tax applies only to cars (not trucks) and is collected by the [IRS](https://en.wikipedia.org/wiki/Internal_Revenue_Service "Internal Revenue Service"). Its purpose is to discourage the production and purchase of fuel-inefficient vehicles. The tax was phased in over ten years with rates increasing over time. It applies only to manufacturers and importers of vehicles, although presumably some or all of the tax is passed along to automobile consumers in the form of higher prices. Only new vehicles are subject to the tax, so no tax is imposed on used car sales. The tax is graduated to apply a higher tax rate for less-fuel-efficient vehicles. To determine the tax rate, manufacturers test all the vehicles at their laboratories for fuel economy. The US [Environmental Protection Agency](https://en.wikipedia.org/wiki/United_States_Environmental_Protection_Agency "United States Environmental Protection Agency") confirms a portion of those tests at an EPA lab.
In some cases, this tax may apply only to certain variants of a given model; for example, the 2004–2006 [Pontiac GTO](https://en.wikipedia.org/wiki/Holden_Monaro#Pontiac_GTO "Holden Monaro") (captive import version of the [Holden Monaro](https://en.wikipedia.org/wiki/Holden_Monaro "Holden Monaro")) did incur the tax when ordered with the four-speed automatic transmission, but did not incur the tax when ordered with the six-speed manual transmission.[\[62\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-64)
#### EPA testing procedure through 2007
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=24 "Edit section: EPA testing procedure through 2007")\]
Two separate fuel economy tests simulate city driving and highway driving. The "city" driving cycle is based on the Urban Dynamometer Driving Schedule or (UDDS) or [FTP-72](https://en.wikipedia.org/wiki/FTP-72 "FTP-72"), defined in [40 CFR](https://en.wikipedia.org/wiki/Title_40_of_the_Code_of_Federal_Regulations "Title 40 of the Code of Federal Regulations") [86\.I](https://www.ecfr.gov/current/title-40/section-86.I). The UDDS cycle starts with a cold engine and makes 23 stops over a period of 31 minutes for an average speed of 20 mph (32 km/h) and a top speed of 56 mph (90 km/h). The UDDS procedure has been updated to [FTP-75](https://en.wikipedia.org/wiki/FTP-75 "FTP-75") by adding a "hot start" cycle which repeats the "cold start" cycle after a 10-minute pause.
The "highway" program or Highway Fuel Economy Driving Schedule ([HWFET](https://en.wikipedia.org/wiki/HWFET "HWFET")) is defined in [40 CFR](https://en.wikipedia.org/wiki/Title_40_of_the_Code_of_Federal_Regulations "Title 40 of the Code of Federal Regulations") [600\.I](https://www.ecfr.gov/current/title-40/section-600.I) and uses a warmed-up engine and makes no stops, averaging 48 mph (77 km/h) with a top speed of 60 mph (97 km/h) over a 10-mile (16 km) distance. A weighted average of city (55%) and highway (45%) fuel economies is used to determine the combined rating and guzzler tax.[\[63\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA_cycles-65)[\[64\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-66)[\[65\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-67) This rating is what is also used for light-duty vehicle [corporate average fuel economy](https://en.wikipedia.org/wiki/Corporate_average_fuel_economy "Corporate average fuel economy") regulations.
Because EPA figures had almost always indicated better efficiency than real-world fuel-efficiency, the EPA has modified the method starting with 2008. Updated estimates are available for vehicles back to the 1985 model year.[\[63\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA_cycles-65)[\[66\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-68)
- [](https://en.wikipedia.org/wiki/File:Uddsdds.gif "The \"city\" or Urban Dynamometer Driving Schedule (UDDS) used in the EPA Federal Test Procedure")
The "city" or Urban Dynamometer Driving Schedule (UDDS) used in the EPA Federal Test Procedure
- [](https://en.wikipedia.org/wiki/File:Hwfetdds.gif "The Highway Fuel Economy Driving Cycle (HWFET) used in the EPA Federal Test Procedure")
The Highway Fuel Economy Driving Cycle (HWFET) used in the EPA Federal Test Procedure
#### EPA testing procedure: 2008 and beyond
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=25 "Edit section: EPA testing procedure: 2008 and beyond")\]
[](https://en.wikipedia.org/wiki/File:Fuel_economy_label_EPA_2008.jpg)
2008 [Monroney sticker](https://en.wikipedia.org/wiki/Monroney_sticker "Monroney sticker") highlights fuel economy.
US EPA altered the testing procedure effective MY2008 which adds three new [Supplemental Federal Test Procedure](https://en.wikipedia.org/wiki/United_States_vehicle_emission_standards#Supplemental_Federal_Test_Procedure_\(SFTP\) "United States vehicle emission standards") (SFTP) tests to include the influence of higher driving speed, harder acceleration, colder temperature and air conditioning use.[\[67\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-2008epa_test-69)
SFTP [US06](https://en.wikipedia.org/wiki/US06 "US06") is a high speed/quick acceleration loop that lasts 10 minutes, covers 8 miles (13 km), averages 48 mph (77 km/h) and reaches a top speed of 80 mph (130 km/h). Four stops are included, and brisk acceleration maximizes at a rate of 8.46 mph (13.62 km/h) per second. The engine begins warm and air conditioning is not used. Ambient temperature varies between 68 °F (20 °C) to 86 °F (30 °C).
SFTP [SC03](https://en.wikipedia.org/wiki/SC03 "SC03") is the air conditioning test, which raises ambient temperatures to 95 °F (35 °C), and puts the vehicle's climate control system to use. Lasting 9.9 minutes, the 3.6-mile (5.8 km) loop averages 22 mph (35 km/h) and maximizes at a rate of 54.8 mph (88.2 km/h). Five stops are included, idling occurs 19 percent of the time and acceleration of 5.1 mph per second is achieved. Engine temperatures begin warm.
Lastly, a cold temperature cycle uses the same parameters as the current city loop, except that ambient temperature is set to 20 °F (−7 °C).
EPA tests for fuel economy do not include electrical load tests beyond climate control, which may account for some of the discrepancy between EPA and real world fuel-efficiency. A 200 W electrical load can produce a 0.4 km/L (0.94 mpg) reduction in efficiency on the FTP 75 cycle test.[\[33\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ieee-35)
Beginning with model year 2017 the calculation method changed to improve the accuracy of the estimated 5-cycle city and highway fuel economy values derived from just the FTP and HFET tests, with lower uncertainty for fuel efficient vehicles.[\[68\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-70)
#### Electric vehicles and hybrids
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=26 "Edit section: Electric vehicles and hybrids")\]
[](https://en.wikipedia.org/wiki/File:Chevy_Volt_EPA_Fuel_Economy_Official_Label.png)
2010 [Monroney sticker](https://en.wikipedia.org/wiki/Monroney_sticker "Monroney sticker") for a [plug-in hybrid](https://en.wikipedia.org/wiki/Plug-in_hybrid "Plug-in hybrid") showing fuel economy in [all-electric mode](https://en.wikipedia.org/wiki/All-electric_mode "All-electric mode") and gasoline-only mode
Following the efficiency claims made for vehicles such as [Chevrolet Volt](https://en.wikipedia.org/wiki/Chevrolet_Volt "Chevrolet Volt") and [Nissan Leaf](https://en.wikipedia.org/wiki/Nissan_Leaf "Nissan Leaf"), the [National Renewable Energy Laboratory](https://en.wikipedia.org/wiki/National_Renewable_Energy_Laboratory "National Renewable Energy Laboratory") recommended to use EPA's new vehicle fuel efficiency formula that gives different values depending on fuel used.[\[69\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-71) In November 2010 the EPA introduced the first fuel economy ratings in the [Monroney stickers](https://en.wikipedia.org/wiki/Monroney_sticker "Monroney sticker") for [plug-in electric vehicles](https://en.wikipedia.org/wiki/Plug-in_electric_vehicle "Plug-in electric vehicle").
For the fuel economy label of the Chevy Volt [plug-in hybrid](https://en.wikipedia.org/wiki/Plug-in_hybrid "Plug-in hybrid") EPA rated the car separately for [all-electric mode](https://en.wikipedia.org/wiki/All-electric_mode "All-electric mode") expressed in [miles per gallon gasoline equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent "Miles per gallon gasoline equivalent") (MPG-e) and for gasoline-only mode expressed in conventional miles per gallon. EPA also estimated an overall combined city/highway gas-electricity fuel economy rating expressed in miles per gallon gasoline equivalent (MPG-e). The label also includes a table showing fuel economy and electricity consumed for five different scenarios: 30 miles (48 km), 45 miles (72 km), 60 miles (97 km) and 75 miles (121 km) driven between a full charge, and a never charge scenario. This information was included to make the consumers aware of the variability of the fuel economy outcome depending on miles driven between charges. Also the fuel economy for a gasoline-only scenario (never charge) was included. For electric-only mode the energy consumption estimated in [kWh](https://en.wikipedia.org/wiki/KWh "KWh") per 100 miles (160 km) is also shown.[\[70\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-GCCEPAVolt-72)[\[71\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPAmpge-73)
[](https://en.wikipedia.org/wiki/File:Nissan_Leaf_EPA_fuel_economy_label.jpg)
2010 [Monroney label](https://en.wikipedia.org/wiki/Monroney_label "Monroney label") showing the EPA's combined city/highway [fuel economy equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent "Miles per gallon gasoline equivalent") for an all-[electric car](https://en.wikipedia.org/wiki/Electric_car "Electric car"), in this case a 2010 [Nissan Leaf](https://en.wikipedia.org/wiki/Nissan_Leaf "Nissan Leaf")
For the fuel economy label of the Nissan Leaf [electric car](https://en.wikipedia.org/wiki/Electric_car "Electric car") EPA rated the combined fuel economy in terms of [miles per gallon gasoline equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent "Miles per gallon gasoline equivalent"), with a separate rating for city and highway driving. This fuel economy equivalence is based on the energy consumption estimated in [kWh](https://en.wikipedia.org/wiki/KWh "KWh") per 100 miles, and also shown in the Monroney label.[\[72\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-NYTEPA-74)
In May 2011, the [National Highway Traffic Safety Administration](https://en.wikipedia.org/wiki/National_Highway_Traffic_Safety_Administration "National Highway Traffic Safety Administration") (NHTSA) and EPA issued a joint final rule establishing new requirements for a [fuel economy and environment label](https://en.wikipedia.org/wiki/Fuel_economy_and_environment_label "Fuel economy and environment label") that is mandatory for all new passenger cars and trucks starting with [model year](https://en.wikipedia.org/wiki/Model_year "Model year") 2013, and voluntary for 2012 models. The ruling includes new labels for [alternative fuel](https://en.wikipedia.org/wiki/Alternative_fuel "Alternative fuel") and [alternative propulsion](https://en.wikipedia.org/wiki/Alternative_propulsion "Alternative propulsion") vehicles available in the US market, such as [plug-in hybrids](https://en.wikipedia.org/wiki/Plug-in_hybrid "Plug-in hybrid"), [electric vehicles](https://en.wikipedia.org/wiki/Electric_vehicle "Electric vehicle"), [flexible-fuel vehicles](https://en.wikipedia.org/wiki/Flexible-fuel_vehicle "Flexible-fuel vehicle"), [hydrogen fuel cell vehicle](https://en.wikipedia.org/wiki/Fuel_cell_vehicle "Fuel cell vehicle"), and [natural gas vehicles](https://en.wikipedia.org/wiki/Natural_gas_vehicle "Natural gas vehicle").[\[73\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA2013-75)[\[74\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-GCC2013-76) The common fuel economy metric adopted to allow the comparison of alternative fuel and advanced technology vehicles with conventional [internal combustion engine](https://en.wikipedia.org/wiki/Internal_combustion_engine "Internal combustion engine") vehicles is [miles per gallon of gasoline equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_of_gasoline_equivalent "Miles per gallon of gasoline equivalent") (MPGe). A gallon of gasoline equivalent means the number of kilowatt-hours of electricity, cubic feet of [compressed natural gas](https://en.wikipedia.org/wiki/Compressed_natural_gas "Compressed natural gas") (CNG), or kilograms of [hydrogen](https://en.wikipedia.org/wiki/Hydrogen "Hydrogen") that is equal to the energy in a gallon of gasoline.[\[73\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA2013-75)
The new labels also include for the first time an estimate of how much fuel or electricity it takes to drive 100 miles (160 km), providing US consumers with fuel consumption per distance traveled, the metric commonly used in many other countries. EPA explained that the objective is to avoid the traditional miles per gallon metric that can be potentially misleading when consumers compare fuel economy improvements, and known as the "MPG illusion"[\[75\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-77) – this illusion arises because the reciprocal (i.e. non-linear) relationship between cost (equivalently, volume of fuel consumed) per unit distance driven and MPG value means that *differences* in MPG values are not directly meaningful – only ratios are (in mathematical terms, the reciprocal function does not commute with addition and subtraction; in general, a difference in reciprocal values is not equal to the reciprocal of their difference). It has been claimed that many consumers are unaware of this, and therefore compare MPG values by subtracting them, which can give a misleading picture of relative differences in fuel economy between different pairs of vehicles – for instance, an increase from 10 to 20 MPG corresponds to a 100% improvement in fuel economy, whereas an increase from 50 to 60 MPG is only a 20% improvement, although in both cases the difference is 10 MPG.[\[76\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-78) The EPA explained that the new gallons-per-100-miles metric provides a more accurate measure of fuel efficiency[\[73\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA2013-75)[\[77\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-79) – notably, it is equivalent to the normal metric measurement of fuel economy, liters per 100 kilometers (L/100 km).
#### CAFE standards
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=27 "Edit section: CAFE standards")\]
Main article: [Corporate Average Fuel Economy](https://en.wikipedia.org/wiki/Corporate_Average_Fuel_Economy "Corporate Average Fuel Economy")
[](https://en.wikipedia.org/wiki/File:CAFE_mpg_curve_from_NHTSA%27s_Summary_of_Fuel_Economy_Performance,_December_2014.svg)
Curve of average car mileage for model years between 1978 and 2014
The Corporate Average Fuel Economy (CAFE) regulations in the United States, first enacted by Congress in 1975,[\[78\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-80) are federal regulations intended to improve the average fuel economy of cars and light trucks (trucks, vans and [sport utility vehicles](https://en.wikipedia.org/wiki/Sport_utility_vehicle "Sport utility vehicle")) sold in the US in the wake of the [1973 Arab Oil Embargo](https://en.wikipedia.org/wiki/1973_oil_crisis "1973 oil crisis"). Historically, it is the sales-weighted average fuel economy of a manufacturer's [fleet](https://en.wikipedia.org/wiki/Fleet_vehicle "Fleet vehicle") of current [model year](https://en.wikipedia.org/wiki/Model_year "Model year") passenger cars or light trucks, manufactured for sale in the United States. Under Truck CAFE standards 2008–2011 this changes to a "footprint" model where larger trucks are allowed to consume more fuel. The standards were limited to vehicles under a certain weight, but those weight classes were expanded in 2011.
#### Federal and state regulations
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=28 "Edit section: Federal and state regulations")\]
The [Clean Air Act](https://en.wikipedia.org/wiki/Clean_Air_Act_\(United_States\) "Clean Air Act (United States)") of 1970 prohibited states from establishing their own air pollution standards. However, the legislation authorized the EPA to grant a waiver to California, allowing the state to set higher standards.[\[79\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-NYTApril18-81) The law provides a “piggybacking” provision that allows other states to adopt vehicle emission limits that are the same as California's.[\[80\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ELQSept03-82) California's waivers were routinely granted until 2007, when the [George W. Bush administration](https://en.wikipedia.org/wiki/Presidency_of_George_W._Bush "Presidency of George W. Bush") rejected the state's bid to adopt global warming pollution limits for cars and light trucks.[\[81\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-NYTDec07-83) California and 15 other states that were trying to put in place the same emissions standards sued in response.[\[82\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-WaPoJan08-84) The case was tied up in court until the [Obama administration](https://en.wikipedia.org/wiki/Presidency_of_Barack_Obama "Presidency of Barack Obama") reversed the policy in 2009 by granting the waiver.[\[83\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-GTMJune09-85)
In August 2012, President Obama announced new standards for American-made automobiles of an average of 54.5 miles per gallon by the year 2025.[\[84\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-86)[\[85\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-87) In April 2018, EPA Administrator [Scott Pruitt](https://en.wikipedia.org/wiki/Scott_Pruitt "Scott Pruitt") announced that the [Trump administration](https://en.wikipedia.org/wiki/First_presidency_of_Donald_Trump "First presidency of Donald Trump") planned to roll back the 2012 federal standards and would also seek to curb California's authority to set its own standards.[\[79\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-NYTApril18-81) Although the Trump administration was reportedly considering a compromise to allow state and national standards to stay in place,[\[86\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-NYT2018-88) on 21 February 2019 the White House declared that it had abandoned these negotiations.[\[87\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-89) A government report subsequently found that, in 2019, new light-duty vehicle fuel economy fell 0.2 miles per gallon (to 24.9 miles per gallon) and pollution increased 3 grams per mile traveled (to 356 grams per mile). A decrease in fuel economy and an increase in pollution had not occurred for the previous five years.[\[88\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-90) The Obama-era rule was officially rolled back on 31 March 2020 during the Trump administration,[\[89\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-91) but the rollback was reversed on 20 December 2021 during the Biden administration.[\[90\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-92)
## Fuel economy of trucks
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=29 "Edit section: Fuel economy of trucks")\]
Trucks are usually bought as an investment good. They are meant to earn money. As the Diesel fuel burnt in heavy trucks accounts for around 30%[\[91\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-:0-93) of the total costs for a freight forwarding company there is always a lot of interest in both the haulage industry and the truck builder industry to strive for best fuel economy. For truck buyers the fuel economy measured by standard procedures is only a first guideline. Professional trucking companies measure the fuel economy of their trucks and truck fleets in real usage. Fuel economy of trucks in real usage is determined by four important factors:[\[91\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-:0-93) The truck technology that is constantly improved by the various OEMs. The driver's driving style contributes a lot to the real fuel economy (different from the test cycles where a standard driving style is used). The maintenance condition of the vehicle influences the fuel efficiency – again different from standardized procedures where the trucks are always presented in flawless condition. Last but not least the usage of the vehicle influences the fuel consumption: Hilly roads and heavy loads will increase the fuel consumption of a vehicle.
## Effect on pollution
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=30 "Edit section: Effect on pollution")\]
Further information: [Gas-guzzler](https://en.wikipedia.org/wiki/Gas-guzzler "Gas-guzzler") and [Vehicle Efficiency Initiative](https://en.wikipedia.org/wiki/Vehicle_Efficiency_Initiative "Vehicle Efficiency Initiative")
Fuel efficiency directly affects emissions causing pollution by affecting the amount of fuel used. However, it also depends on the fuel source used to drive the vehicle concerned. Cars for example, can run on a number of fuel types other than gasoline, such as [natural gas](https://en.wikipedia.org/wiki/Natural_gas_vehicle "Natural gas vehicle"), [LPG](https://en.wikipedia.org/wiki/Liquefied_petroleum_gas "Liquefied petroleum gas") or [biofuel](https://en.wikipedia.org/wiki/Biofuel "Biofuel") or electricity which creates various quantities of atmospheric pollution.
A kilogram of carbon, whether contained in petrol, diesel, kerosene, or any other hydrocarbon fuel in a vehicle, leads to approximately 3.6 kg of [CO2](https://en.wikipedia.org/wiki/CO2 "CO2") emissions.[\[92\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA_CO2_est-94) Due to the carbon content of gasoline, its combustion emits 2.3 kg/L (19.4 lb/US gal) of [CO2](https://en.wikipedia.org/wiki/CO2 "CO2"); since diesel fuel is more energy dense per unit volume, diesel emits 2.6 kg/L (22.2 lb/US gal).[\[92\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA_CO2_est-94) This figure is only the CO2 emissions of the final fuel product and does not include additional CO2 emissions created during the drilling, pumping, transportation and refining steps required to produce the fuel. Additional measures to reduce overall emission includes improvements to the efficiency of [air conditioners](https://en.wikipedia.org/wiki/Air_conditioner "Air conditioner"), lights and tires.
## Unit conversions
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=31 "Edit section: Unit conversions")\]
US Gallons
- 1 mpg ≈ 0.425 km/L
- 235\.2/mpg ≈ L/100 km
- 1 mpg ≈ 1.201 mpg (imp)
Imperial gallons
- 1 mpg ≈ 0.354 km/L
- 282/mpg ≈ L/100 km
- 1 mpg ≈ 0.833 mpg (US)
### Conversion from mpg
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=32 "Edit section: Conversion from mpg")\]
| | | | |
|---|---|---|---|
| mpg (imp) | mpg (US) | km/L | L/100 km |
| 5 | 4\.2 | 1\.8 | 56\.5 |
| 10 | 8\.3 | 3\.5 | 28\.2 |
| 15 | 12\.5 | 5\.3 | 18\.8 |
| 20 | 16\.7 | 7\.1 | 14\.1 |
| 25 | 20\.8 | 8\.9 | 11\.3 |
| 30 | 25\.0 | 10\.6 | 9\.4 |
| 35 | 29\.1 | 12\.4 | 8\.1 |
| 40 | 33\.3 | 14\.2 | 7\.1 |
| 45 | 37\.5 | 15\.9 | 6\.3 |
| 50 | 41\.6 | 17\.7 | 5\.6 |
| 55 | 45\.8 | 19\.5 | 5\.1 |
| 60 | 50\.0 | 21\.2 | 4\.7 |
| 65 | 54\.1 | 23\.0 | 4\.3 |
| 70 | 58\.3 | 24\.8 | 4\.0 |
| 75 | 62\.5 | 26\.6 | 3\.8 |
| 80 | 66\.6 | 28\.3 | 3\.5 |
| 85 | 70\.8 | 30\.1 | 3\.3 |
| 90 | 74\.9 | 31\.9 | 3\.1 |
| 95 | 79\.1 | 33\.6 | 3\.0 |
| 100 | 83\.3 | 35\.4 | 2\.8 |
| mpg (US) | mpg (imp) | km/L | L/100 km |
| 5 | 6\.0 | 2\.1 | 47\.0 |
| 10 | 12\.0 | 4\.3 | 23\.5 |
| 15 | 18\.0 | 6\.4 | 15\.7 |
| 20 | 24\.0 | 8\.5 | 11\.8 |
| 25 | 30\.0 | 10\.6 | 9\.4 |
| 30 | 36\.0 | 12\.8 | 7\.8 |
| 35 | 42\.0 | 14\.9 | 6\.7 |
| 40 | 48\.0 | 17\.0 | 5\.9 |
| 45 | 54\.0 | 19\.1 | 5\.2 |
| 50 | 60\.0 | 21\.3 | 4\.7 |
| 55 | 66\.1 | 23\.4 | 4\.3 |
| 60 | 72\.1 | 25\.5 | 3\.9 |
| 65 | 78\.1 | 27\.6 | 3\.6 |
| 70 | 84\.1 | 29\.8 | 3\.4 |
| 75 | 90\.1 | 31\.9 | 3\.1 |
| 80 | 96\.1 | 34\.0 | 2\.9 |
| 85 | 102\.1 | 36\.1 | 2\.8 |
| 90 | 108\.1 | 38\.3 | 2\.6 |
| 95 | 114\.1 | 40\.4 | 2\.5 |
| 100 | 120\.1 | 42\.5 | 2\.4 |
### Conversion from km/L and L/100 km
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=33 "Edit section: Conversion from km/L and L/100 km")\]
| | | | |
|---|---|---|---|
| L/100 km | km/L | mpg (US) | mpg (imp) |
| 1 | 100\.0 | 235\.2 | 282\.5 |
| 2 | 50\.0 | 117\.6 | 141\.2 |
| 3 | 33\.3 | 78\.4 | 94\.2 |
| 4 | 25\.0 | 58\.8 | 70\.6 |
| 5 | 20\.0 | 47\.0 | 56\.5 |
| 6 | 16\.7 | 39\.2 | 47\.1 |
| 7 | 14\.3 | 33\.6 | 40\.4 |
| 8 | 12\.5 | 29\.4 | 35\.3 |
| 9 | 11\.1 | 26\.1 | 31\.4 |
| 10 | 10\.0 | 23\.5 | 28\.2 |
| 15 | 6\.7 | 15\.7 | 18\.8 |
| 20 | 5\.0 | 11\.8 | 14\.1 |
| 25 | 4\.0 | 9\.4 | 11\.3 |
| 30 | 3\.3 | 7\.8 | 9\.4 |
| 35 | 2\.9 | 6\.7 | 8\.1 |
| 40 | 2\.5 | 5\.9 | 7\.1 |
| 45 | 2\.2 | 5\.2 | 6\.3 |
| 50 | 2\.0 | 4\.7 | 5\.6 |
| 55 | 1\.8 | 4\.3 | 5\.1 |
| 60 | 1\.7 | 3\.9 | 4\.7 |
| km/L | L/100 km | mpg (US) | mpg (imp) |
| 5 | 20\.0 | 11\.8 | 14\.1 |
| 10 | 10\.0 | 23\.5 | 28\.2 |
| 15 | 6\.7 | 35\.3 | 42\.4 |
| 20 | 5\.0 | 47\.0 | 56\.5 |
| 25 | 4\.0 | 58\.8 | 70\.6 |
| 30 | 3\.3 | 70\.6 | 84\.7 |
| 35 | 2\.9 | 82\.3 | 98\.9 |
| 40 | 2\.5 | 94\.1 | 113\.0 |
| 45 | 2\.2 | 105\.8 | 127\.1 |
| 50 | 2\.0 | 117\.6 | 141\.2 |
| 55 | 1\.8 | 129\.4 | 155\.4 |
| 60 | 1\.7 | 141\.1 | 169\.5 |
| 65 | 1\.5 | 152\.9 | 183\.6 |
| 70 | 1\.4 | 164\.7 | 197\.7 |
| 75 | 1\.3 | 176\.4 | 211\.9 |
| 80 | 1\.3 | 188\.2 | 226\.0 |
| 85 | 1\.2 | 199\.9 | 240\.1 |
| 90 | 1\.1 | 211\.7 | 254\.2 |
| 95 | 1\.1 | 223\.5 | 268\.4 |
| 100 | 1\.0 | 235\.2 | 282\.5 |
## See also
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=34 "Edit section: See also")\]
- [Automobile costs](https://en.wikipedia.org/wiki/Automobile_costs "Automobile costs")
- [ACEA agreement](https://en.wikipedia.org/wiki/ACEA_agreement "ACEA agreement")
- [Battery electric vehicle](https://en.wikipedia.org/wiki/Battery_electric_vehicle "Battery electric vehicle")
- [Car speed and energy consumption](https://en.wikipedia.org/wiki/Car_speed_and_energy_consumption "Car speed and energy consumption")
- [Car tuning](https://en.wikipedia.org/wiki/Car_tuning "Car tuning")
- [Climate crisis](https://en.wikipedia.org/wiki/Climate_crisis "Climate crisis")
- [Emission standard](https://en.wikipedia.org/wiki/Emission_standard "Emission standard")
- [Energy conservation](https://en.wikipedia.org/wiki/Energy_conservation "Energy conservation")
- [Energy-efficient driving](https://en.wikipedia.org/wiki/Energy-efficient_driving "Energy-efficient driving")
- [FF layout](https://en.wikipedia.org/wiki/FF_layout "FF layout")
- [Fuel efficiency in transportation](https://en.wikipedia.org/wiki/Fuel_efficiency_in_transportation "Fuel efficiency in transportation")
- [Fuel saving devices](https://en.wikipedia.org/wiki/Fuel_saving_devices "Fuel saving devices")
- [Gasoline gallon equivalent](https://en.wikipedia.org/wiki/Gasoline_gallon_equivalent "Gasoline gallon equivalent")
- [Motorized quadricycle](https://en.wikipedia.org/wiki/Motorized_quadricycle "Motorized quadricycle") (vehicles with low power engines/low top speed)
- [Miles per gallon gasoline equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent "Miles per gallon gasoline equivalent")
- [Passenger miles per gallon](https://en.wikipedia.org/wiki/Passenger_miles_per_gallon "Passenger miles per gallon")
- [The Very Light Car](https://en.wikipedia.org/wiki/The_Very_Light_Car "The Very Light Car")
- [Vehicle Efficiency Initiative](https://en.wikipedia.org/wiki/Vehicle_Efficiency_Initiative "Vehicle Efficiency Initiative")
- [Vehicle metrics](https://en.wikipedia.org/wiki/Vehicle_metrics "Vehicle metrics")
- [Green vehicle](https://en.wikipedia.org/wiki/Green_vehicle "Green vehicle")
- [Low-carbon economy](https://en.wikipedia.org/wiki/Low-carbon_economy "Low-carbon economy")
- [Low-rolling resistance tires](https://en.wikipedia.org/wiki/Low-rolling_resistance_tires "Low-rolling resistance tires")
- [Microcar](https://en.wikipedia.org/wiki/Microcar "Microcar")
- [Plug-in hybrid](https://en.wikipedia.org/wiki/Plug-in_hybrid "Plug-in hybrid")
## Annotations
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=35 "Edit section: Annotations")\]
1. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-7)** Specifically, the production-weighted [harmonic mean](https://en.wikipedia.org/wiki/Harmonic_mean "Harmonic mean")
2. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-16)** The 2.2% drop figure was calculated by finding daily consumption to be 9,299,684 barrels of petroleum. Obtain 1973's petroleum consumption from transportation sector at 2.1e from the Energy Consumption by Sector section, then convert to barrels using A1 in the Thermal Conversion Factors section (assume "conventional motor gasoline" since ethanol-based or purportedly smog-reducing gas was not common in 1973).[\[14\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-15)
## References
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=36 "Edit section: References")\]
1. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-1)**
Page, Walter Hines; Page, Arthur Wilson (1916). ["Man and His Machines"](https://books.google.com/books?id=lPAMVa7esS4C). *The World's Work*. Vol. XXXIII. Garden City, New York: Doubleday, Page & Co.
2. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-2)**
["What counts as 'good' MPG nowadays?"](https://www.thejournal.ie/dear-driver-what-is-good-mpg-3150884-Dec2016/). 21 December 2016.
3. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-3)** [The New Fuel Economy Label](https://www.fueleconomy.gov/feg/label/learn-more-gasoline-label.shtml) at FuelEconomy.gov
4. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA_AutomotiveTrends_202212_4-0)**
["Highlights of the Automotive Trends Report"](https://www.epa.gov/automotive-trends/highlights-automotive-trends-report). *EPA.gov*. U.S. Environmental Protection Agency (EPA). 12 December 2022. [Archived](https://web.archive.org/web/20230902145941/https://www.epa.gov/automotive-trends/highlights-automotive-trends-report) from the original on 2 September 2023.
5. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-GlobalFuelEfficInit_202311_5-0)**
Cazzola, Pierpaolo; Paoli, Leonardo; Teter, Jacob (November 2023). ["Trends in the Global Vehicle Fleet 2023 / Managing the SUV Shift and the EV Transition"](https://www.globalfueleconomy.org/media/792523/gfei-trends-in-the-global-vehicle-fleet-2023-spreads.pdf) (PDF). Global Fuel Economy Initiative (GFEI). p. 3. [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.7922/G2HM56SV](https://doi.org/10.7922%2FG2HM56SV). [Archived](https://web.archive.org/web/20231126092826/https://www.globalfueleconomy.org/media/792523/gfei-trends-in-the-global-vehicle-fleet-2023-spreads.pdf) (PDF) from the original on 26 November 2023.
6. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-6)**
Paul R. Portney; Ian W.H. Parry; Howard K. Gruenspecht; Winston Harrington (November 2003). ["The Economics of Fuel Economy Standards"](https://web.archive.org/web/20071201031917/http://www.rff.org/documents/RFF-DP-03-44.pdf) (PDF). Resources for the Future. Archived from [the original](http://www.rff.org/documents/RFF-DP-03-44.pdf) (PDF) on 1 December 2007. Retrieved 4 January 2008.
`{{cite journal}}`: Cite journal requires `|journal=` ([help](https://en.wikipedia.org/wiki/Help:CS1_errors#missing_periodical "Help:CS1 errors"))
7. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-8)**
["Highlights of the Automotive Trends Report"](https://www.epa.gov/automotive-trends/highlights-automotive-trends-report). *US EPA*. November 2021. Retrieved 30 November 2021.
8. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-2019_epa_BestandWorst_9-0)**
["2019 Best and Worst Fuel Economy Vehicles"](https://www.fueleconomy.gov/feg/best-worst.shtml). US EPA. Retrieved 23 June 2019.
9. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-10)** [Reducing CO2 emissions from passenger cars – Policies – Climate Action – European Commission](http://ec.europa.eu/clima/policies/transport/vehicles/cars_en.htm). Ec.europa.eu (9 December 2010). Retrieved 21 September 2011.
10. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-11)** [Myth: Cars are becoming more fuel efficient](http://www.ptua.org.au/myths/efficient.shtml). Ptua.org.au. Retrieved 21 September 2011.
11. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-pew_12-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-pew_12-1) [***c***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-pew_12-2) [Comparison of Passenger Vehicle Fuel Economy and GHG Emission Standards Around the World at Pew Center on Global Climate Change](http://www.pewclimate.org/docUploads/Fuel%20Economy%20and%20GHG%20Standards_010605_110719.pdf) [Archived](https://web.archive.org/web/20080413221041/http://www.pewclimate.org/docUploads/Fuel%20Economy%20and%20GHG%20Standards_010605_110719.pdf) 13 April 2008 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). (PDF). Retrieved 21 September 2011.
12. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ornl_13-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ornl_13-1) [***c***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ornl_13-2) [Steady Speed Fuel Economy](http://cta.ornl.gov/data/tedb31/Edition31_Full_Doc.pdf) [Archived](https://web.archive.org/web/20120924201205/http://cta.ornl.gov/data/tedb31/Edition31_Full_Doc.pdf) 24 September 2012 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine") "The two earlier studies by the Federal Highway Administration (FHWA) indicate maximum fuel efficiency was achieved at speeds of 35 to 40 mph (55 to 65 km/h). The recent FHWA study indicates greater fuel efficiency at higher speeds."
13. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-14)**
Cowan, Edward (27 November 1973). "Politics and Energy: Nixon's Silence on Rationing Reflects Hope That Austerity Can Be Avoided". *The New York Times*. p. 30.
14. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-15)**
Staff (28 June 2008). [*Annual Energy Review*](https://web.archive.org/web/20180926014110/https://www.eia.gov/FTPROOT/multifuel/038407.pdf) (PDF) (2007 ed.). Washington, DC: Energy Information Administration. Archived from [the original](https://www.eia.gov/FTPROOT/multifuel/038407.pdf) (PDF) on 26 September 2018.
15. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-17)**
["55 Mile-per-hour Speed Limit Approved by House"](http://infoweb.newsbank.com/iw-search/we/HistArchive/?p_action=doc&p_queryname=3&p_docid=0FCAA40565438742&p_docnum=20&s_pagesearch=no&s_ARTICLE_ID=0FCAA40565438742&s_RELEASE=release_0005&s_ISSUE_ID=0FCAA4036C446D57&s_FORMAT=gif&s_SIZE=display&s_SEARCHED=%28+%28%28pty%253A10+%29+OR+%28pty%253A40+%29+OR+%28pty%253A50+%29+OR+%28pty%253A60+%29%29+%29+and+%28+ibd%253A%255B2441684%253B2442414%255D+%29+and+%28+%2855%29+AND+%28speed++AND+limit%29+%29+&p_product=DMHA&p_theme=dmn&p_nbid=R5FY50FIMTIxNjc0NDY1Mi4yNjE1OjE6MTU6MTI5LjExOS4yNDguMjUx). [United Press International](https://en.wikipedia.org/wiki/United_Press_International "United Press International"). 4 December 1973. p. 30. Retrieved 22 July 2008.
(subscription required)
16. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-18)**
["Special Report 254: Managing Speed"](https://onlinepubs.trb.org/onlinepubs/sr/sr254.pdf) (PDF). [Transportation Research Board](https://en.wikipedia.org/wiki/Transportation_Research_Board "Transportation Research Board"): 189. Retrieved 17 September 2014. "Bloomquist (1984) estimated that the 1974 National Maximum Speed Limit (NMSL) reduced fuel consumption by 0.2 to 1.0 percent."
`{{cite journal}}`: Cite journal requires `|journal=` ([help](https://en.wikipedia.org/wiki/Help:CS1_errors#missing_periodical "Help:CS1 errors"))
17. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-19)**
["Highway Statistics 1973 (Table VM-2: VEHICLE MILES, BY STATE AND HIGHWAY SYSTEM-1973)"](https://web.archive.org/web/20130304135803/http://isddc.dot.gov/OLPFiles/FHWA/012894.pdf) (PDF). [Federal Highway Administration](https://en.wikipedia.org/wiki/Federal_Highway_Administration "Federal Highway Administration"): 76. Archived from [the original](http://isddc.dot.gov/OLPFiles/FHWA/012894.pdf) (PDF) on 4 March 2013. Retrieved 17 September 2014.
`{{cite journal}}`: Cite journal requires `|journal=` ([help](https://en.wikipedia.org/wiki/Help:CS1_errors#missing_periodical "Help:CS1 errors"))
18. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-greenvehicleguide.gov.au_20-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-greenvehicleguide.gov.au_20-1)
["Lexus IS250 2.5L 6cyl, Auto 6 speed Sedan, 5 seats, 2WD"](http://www.greenvehicleguide.gov.au/GVGPublicUI/CompareVehicles.aspx).
`{{cite web}}`: CS1 maint: deprecated archival service ([link](https://en.wikipedia.org/wiki/Category:CS1_maint:_deprecated_archival_service "Category:CS1 maint: deprecated archival service"))
19. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-lexus.de_21-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-lexus.de_21-1)
*IS 250 Kraftstoffverbrauch kombiniert 8,9 L/100 km (innerorts 12,5 L/ außerorts 6,9 L) bei CO2-Emissionen von 209 g/km nach dem vorgeschriebenen EU-Messverfahren*
["LEXUS – Lexus – IS – Sportlimousine – Cabriolet – Cabrio – Kabrio – Coupé – Coupe – Hochleistung IS F – High-Performance-Fahrzeug IS F"](https://web.archive.org/web/20100402102635/http://www.lexus.de/range/IS/Index.aspx). Archived from [the original](http://www.lexus.de/range/is/index.aspx) on 2 April 2010. Retrieved 22 April 2010.
20. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-fueleconomy.gov_22-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-fueleconomy.gov_22-1) *2009 Lexus IS 250 6 cyl, 2.5 L, Automatic (S6), Premium* [http://www.fueleconomy.gov/feg/findacar.htm](https://www.fueleconomy.gov/feg/findacar.htm)
21. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-23)**
["Gas prices too high? Try Europe"](https://www.csmonitor.com/2005/0826/p01s03-woeu.html). *Christian Science Monitor*. 26 August 2005. [Archived](https://web.archive.org/web/20120918025725/http://www.csmonitor.com/2005/0826/p01s03-woeu.html) from the original on 18 September 2012.
22. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-24)**
["U.S. 'stuck in reverse' on fuel economy"](https://web.archive.org/web/20141206112123/http://www.nbcnews.com/id/17344368/). *[NBC News](https://en.wikipedia.org/wiki/NBC_News "NBC News")*. 28 February 2007. Archived from [the original](http://www.nbcnews.com/id/17344368) on 6 December 2014.
23. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-25)**
["VW Lupo: Rough road to fuel economy"](http://usatoday30.usatoday.com/money/consumer/autos/mareview/mauto497.htm).
24. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-26)** [Heavy Vehicles and Characteristics](http://cta.ornl.gov/data/chapter5.shtml) [Archived](https://web.archive.org/web/20120723162849/http://cta.ornl.gov/data/chapter5.shtml) 2012-07-23 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine") Table 5.4
25. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-27)** [Light Vehicles and Characteristics](http://cta.ornl.gov/data/chapter4.shtml) [Archived](https://web.archive.org/web/20120915163525/http://cta.ornl.gov/data/chapter4.shtml) 2012-09-15 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine") Table 4.1
26. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-28)** [How Do Gasoline Prices Affect Fleet Fuel Economy?](http://www.aeaweb.org/articles.php?doi=10.1257/pol.1.2.113) [Archived](https://web.archive.org/web/20121021131856/http://www.aeaweb.org/articles.php?doi=10.1257%2Fpol.1.2.113) 2012-10-21 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine")
27. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-twsMercuryNews_29-0)** Dee-Ann Durbin of the Associated Press, June 17, 2014, Mercury News, [Auto industry gets serious about lighter materials](http://www.mercurynews.com/business/ci_25981045/auto-industry-gets-serious-about-lighter-materials) [Archived](https://web.archive.org/web/20150415082011/http://www.mercurynews.com/business/ci_25981045/auto-industry-gets-serious-about-lighter-materials) 2015-04-15 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"), Retrieved April 11, 2015, "...Automakers have been experimenting for decades with lightweighting... the effort is gaining urgency with the adoption of tougher gas mileage standards. ..."
28. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-30)**
Yang, Zifei; Bandivadekar, Anup. ["Light-duty vehicle greenhouse gas and fuel economy standards"](http://www.theicct.org/sites/default/files/publications/2017-Global-LDV-Standards-Update_ICCT-Report_23062017_vF.pdf) (PDF). International Council on Clean Transportation. Retrieved 1 December 2017.
29. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-31)**
["Lexus IS – Driving in every sense"](https://www.lexus.ca/lexus/en/automobiles/is#intro_text). *Lexus Canada*.
30. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-32)**
["TRANSPORTATION RESEARCH BOARD SPECIAL REPORT 286 TIRES AND PASSENGER VEHICLE FUEL ECONOMY, Transportation Research Board, National Academy of Sciences p.62-65 of pdf, p.39-42 of the report. Retrieved 22 October 2014"](https://onlinepubs.trb.org/onlinepubs/sr/sr286.pdf) (PDF).
31. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-33)** [Wheels, online road load, and MPG calculator](http://www.virtual-car.org/wheels/wheels-road-load-calculation.html). Virtual-car.org (3 August 2009). Retrieved 21 September 2011.
32. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-34)** [An Overview of Current Automatic, Manual and Continuously Variable Transmission Efficiencies and Their Projected Future Improvements](http://www.sae.org/servlets/productDetail?PROD_TYP=PAPER&PROD_CD=1999-01-1259). SAE.org (1 March 1999). Retrieved 21 September 2011.
33. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ieee_35-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ieee_35-1) [Automotive Electrical Systems Circa 2005](http://www.spectrum.ieee.org/print/1420) [Archived](https://web.archive.org/web/20090203012939/http://www.spectrum.ieee.org/print/1420) 3 February 2009 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). Spectrum.ieee.org. Retrieved 21 September 2011.
34. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-36)** [Low-rolling resistance tires](https://en.wikipedia.org/wiki/Low-rolling_resistance_tires "Low-rolling resistance tires")
35. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-37)**
Chandler, David (9 February 2009). ["More power from bumps in the road"](https://web.mit.edu/newsoffice/2009/shock-absorbers-0209.html). Retrieved 8 October 2009.
36. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-38)** [Gas Saving and Emission Reduction Devices Evaluation \| Cars and Light Trucks \| US EPA](https://archive.today/20120729113626/http://www.epa.gov/otaq/consumer/reports.htm). Epa.gov. Retrieved 21 September 2011.
37. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-39)** <https://onfuel.appspot.com> keep track of fuel efficiency
38. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-40)**
["Anglian Water spot on with pressure test"](http://www.tyrepress.com/2015/10/anglian-water-spot-on-with-pressure-test/). *Tyrepress*. 29 October 2015. Retrieved 30 October 2015.
39. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-41)** [Chinese Fuel Economy Laws](http://www.treehugger.com/files/2005/07/chinese_fuel_ec.php). Treehugger.com. Retrieved 21 September 2011.
40. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-42)**
Cox, Lisa (30 March 2019). ["'Woefully dirty': Government accused over Australia's failure to cut vehicle emissions"](https://www.theguardian.com/environment/2019/mar/31/government-accused-australia-failure-cut-vehicle-emissions). *The Guardian*.
41. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-43)** [Vehicles & the Environment](http://www.infrastructure.gov.au/roads/environment/index.aspx). Infrastructure.gov.au. Retrieved 21 September 2011.
42. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-44)** [Information on Green Vehicle Guide Ratings and Measurement](https://web.archive.org/web/20110716024739/http://www.greenvehicleguide.gov.au/GVGPublicUI/home.aspx). Australian Department of Infrastructure and Transport
43. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-45)** [Green Vehicle Guide](http://www.greenvehicleguide.gov.au/) [Archived](https://web.archive.org/web/20060422230409/http://www.greenvehicleguide.gov.au/) 22 April 2006 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). Green Vehicle Guide. Retrieved 21 September 2011.
44. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-nrcan.gc.ca_46-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-nrcan.gc.ca_46-1)
["5-cycle testing"](https://www.nrcan.gc.ca/energy/efficiency/transportation/cars-light-trucks/buying/7495). *nrcan.gc.ca*. 30 April 2018.
45. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-47)** [Vehicle test cycles](http://herkules.oulu.fi/isbn9514269543/html/x787.html). Herkules.oulu.fi. Retrieved 21 September 2011.
46. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-48)**
["News & Events"](https://www.honda.de/cars/world-of-honda/news-events.html). *www.honda.de*. Retrieved 2 May 2023.
47. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-49)**
["2011 Honda CR-Z Specs and Features"](https://autos.msn.com/research/vip/Spec_Glance.aspx?year=2011&make=Honda&model=CR-Z). Retrieved 2 May 2023.
\[*[permanent dead link](https://en.wikipedia.org/wiki/Wikipedia:Link_rot "Wikipedia:Link rot")*\]
48. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-50)** [Guidance notes and examples](http://www.vca.gov.uk/additional/files/fcb--co2/enforcement-on-advertising/vca061.pdf) [Archived](https://web.archive.org/web/20080413221042/http://www.vca.gov.uk/additional/files/fcb--co2/enforcement-on-advertising/vca061.pdf) 13 April 2008 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). (PDF). Retrieved 21 September 2011.
49. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-51)** [Fuel Economy Label](http://www.dft.gov.uk/actonco2/index.php?q=fuel_economy_sticker) [Archived](https://web.archive.org/web/20080814112511/http://www.dft.gov.uk/ActOnCO2/index.php?q=fuel_economy_sticker) 14 August 2008 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). Dft.gov.uk. Retrieved 21 September 2011.
50. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-52)** [Vehicle Labelling](http://www.environ.ie/en/Environment/Atmosphere/ClimateChange/VehicleLabelling/) [Archived](https://web.archive.org/web/20080707012035/http://www.environ.ie/en/Environment/Atmosphere/ClimateChange/VehicleLabelling/) 7 July 2008 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). Environ.ie (1 July 2008). Retrieved 21 September 2011.
51. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-53)**
["Regulation (EU) 2019/631 of the European Parliament and of the Council of 17 April 2019 setting CO2 emission performance standards for new passenger cars and for new light commercial vehicles, and repealing Regulations (EC) No 443/2009 and (EU) No 510/2011 (Text with EEA relevance.)"](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A32019R0631). [European Union](https://en.wikipedia.org/wiki/European_Union "European Union"). 25 April 2019. "Annex 1, Part A.6 NEDC2020, Fleet Target is 95 g/km. (45) Manufacturers whose average specific emissions of CO2 exceed those permitted under this Regulation should pay an excess emissions premium with respect to each calendar year."
52. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-54)**
["Why the EC figures do not represent true MPG"](https://www.honestjohn.co.uk/realmpg/why-are-the-ec-figures-so-optimistic-true-mpg/). *Honest John*. Retrieved 14 November 2015.
53. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-55)**
["Real Life Fuel Economy (MPG) Register"](http://www.honestjohn.co.uk/realmpg/). *Honest John*. Retrieved 14 November 2015.
54. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-56)**
["Cars and Garages: Diagnose Problems, Estimate Costs & Find Garages"](http://www.carsandgarages.co.uk/news/29-ASA-says-fuel-consumption-figures-are-mis). *carsandgarages.co.uk*.
55. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-57)**
Mike Millikin (28 September 2014). ["ICCT: gap between official and real-world fuel economy figures in Europe reaches ~38%; call to implement WLTP ASAP"](http://www.greencarcongress.com/2014/09/20140928-icct.html). [Green Car Congress](https://en.wikipedia.org/w/index.php?title=Green_Car_Congress&action=edit&redlink=1 "Green Car Congress (page does not exist)"). Retrieved 28 September 2014.
56. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-58)** [From laboratory to road: A 2018 update](https://www.theicct.org/publications/laboratory-road-2018-update) ICCT, 2019
57. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-JapTest01_59-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-JapTest01_59-1)
[Japan Automobile Manufacturers Association](https://en.wikipedia.org/wiki/Japan_Automobile_Manufacturers_Association "Japan Automobile Manufacturers Association") (JAMA) (2009). ["From 10•15 to JC08: Japan's new economy formula"](http://www.jama-english.jp/europe/news/2009/no_2/peternunn.html). News from JAMA. Retrieved 9 April 2012.
*Issue No. 2, 2009*.
58. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-JapTest02_60-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-JapTest02_60-1)
["Japanese 10–15 Mode"](https://www.dieselnet.com/standards/cycles/jp_10-15mode.php). Diesel.net. Retrieved 9 April 2012.
59. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-61)**
["Prius Certified to Japanese 2015 Fuel Economy Standards with JC08 Test Cycle"](http://www.greencarcongress.com/2007/08/prius-certified.html). [Green Car Congress](https://en.wikipedia.org/w/index.php?title=Green_Car_Congress&action=edit&redlink=1 "Green Car Congress (page does not exist)"). 11 August 2007. Retrieved 9 April 2012.
60. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-62)**
["Vehicle Fuel Economy Labelling – FAQs"](https://web.archive.org/web/20080710061145/http://www.eeca.govt.nz/transport/vehicle-fuel-economy/faqs.htm). Archived from [the original](http://www.eeca.govt.nz/transport/vehicle-fuel-economy/faqs.htm) on 10 July 2008. Retrieved 2 May 2023.
61. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-63)** [Frequently Asked Questions](https://www.fueleconomy.gov/feg/info.shtml#guzzler). Fueleconomy.gov. Retrieved 21 September 2011.
62. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-64)**
Steven Cole Smith (28 April 2005). ["2005 Pontiac GTO"](https://web.archive.org/web/20150511195355/http://www.cars.com/pontiac/gto/2005/reviews/?revid=47269). Orlando Sentinel via Cars.com. Archived from [the original](http://www.cars.com/pontiac/gto/2005/reviews/?revid=47269) on 11 May 2015. Retrieved 21 February 2011.
63. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA_cycles_65-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA_cycles_65-1)
["Dynamometer Driver's Aid"](https://web.archive.org/web/20140330111359/http://www.epa.gov/nvfel/testing/dynamometer.htm). US EPA. Archived from [the original](http://www.epa.gov/nvfel/testing/dynamometer.htm) on 30 March 2014. Retrieved 11 January 2011.
64. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-66)** [How the EPA Tests and Rates Fuel Economy](https://auto.howstuffworks.com/28004-epa-fuel-economy-explained1.htm). Auto.howstuffworks.com (7 September 2005). Retrieved 21 September 2011.
65. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-67)** [Gasoline Vehicles: Learn More About the Label](https://fueleconomy.gov/feg/label/learn-more-gasoline-label.shtml). Retrieved 10 July 2020.
66. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-68)** [Find a Car 1985 to 2009](https://www.fueleconomy.gov/feg/findacar.htm). Fueleconomy.gov. Retrieved 21 September 2011.
67. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-2008epa_test_69-0)**
["2008 Ratings Changes"](https://www.fueleconomy.gov/feg/fe_test_schedules.shtml). US EPA. Retrieved 17 April 2013.
68. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-70)**
US EPA United States Environmental Protection Agency. ["Basic Search"](https://web.archive.org/web/20170122021353/https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=35113&flag=1). Iaspub.epa.gov. Archived from [the original](https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=35113&flag=1) on 22 January 2017. Retrieved 1 September 2022.
69. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-71)** Roth, Dan. (1 October 2009) [REPORT: EPA planning to address outlandish fuel economy claims of electric cars](http://www.autoblog.com/2009/10/01/report-epa-planning-to-address-outlandish-fuel-economy-claims-o/). Autoblog.com. Retrieved 21 September 2011.
70. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-GCCEPAVolt_72-0)**
["Volt receives EPA ratings and label: 93 mpg-e all-electric, 37 mpg gas-only, 60 mpg-e combined"](http://www.greencarcongress.com/2010/11/volt-20101124.html#more). [Green Car Congress](https://en.wikipedia.org/w/index.php?title=Green_Car_Congress&action=edit&redlink=1 "Green Car Congress (page does not exist)"). 24 November 2010. Retrieved 24 November 2010.
71. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPAmpge_73-0)**
[US Environmental Protection Agency](https://en.wikipedia.org/wiki/US_Environmental_Protection_Agency "US Environmental Protection Agency") and [US Department of Energy](https://en.wikipedia.org/wiki/US_Department_of_Energy "US Department of Energy") (4 May 2011). ["2011 Chevrolet Volt"](https://www.fueleconomy.gov/feg/phevsbs.shtml). Fueleconomy.gov. Retrieved 21 May 2011.
72. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-NYTEPA_74-0)**
Nick Bunkley (22 November 2010). ["Nissan Says Its Electric Leaf Gets Equivalent of 99 M.P.G."](https://www.nytimes.com/2010/11/23/business/23leaf.html?_r=1&hpw) *The New York Times*. Retrieved 23 November 2010.
73. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA2013_75-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA2013_75-1) [***c***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA2013_75-2)
EPA (May 2011). ["Fact Sheet: New Fuel Economy and Environment Labels for a New Generation of Vehicles"](https://web.archive.org/web/20110529061246/http://www.epa.gov/otaq/carlabel/420f11017.htm). [US Environmental Protection Agency](https://en.wikipedia.org/wiki/US_Environmental_Protection_Agency "US Environmental Protection Agency"). Archived from [the original](http://www.epa.gov/otaq/carlabel/420f11017.htm) on 29 May 2011. Retrieved 25 May 2011.
*EPA-420-F-11-017*
74. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-GCC2013_76-0)**
["EPA, DOT unveil the next generation of fuel economy labels"](http://www.greencarcongress.com/2011/05/felabel-20110525.html). [Green Car Congress](https://en.wikipedia.org/w/index.php?title=Green_Car_Congress&action=edit&redlink=1 "Green Car Congress (page does not exist)"). 25 May 2011. Retrieved 25 May 2011.
75. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-77)**
["Not All Fuel Efficiency Is Equal: Understanding the Miles-Per-Gallon Illusion"](https://web.archive.org/web/20140115125904/http://www.businessweek.com/articles/2014-01-14/not-all-fuel-efficiency-is-equal-understanding-the-miles-per-gallon-illusion). *Bloomberg.com*. 14 January 2014. Archived from [the original](http://www.businessweek.com/articles/2014-01-14/not-all-fuel-efficiency-is-equal-understanding-the-miles-per-gallon-illusion) on 15 January 2014. Retrieved 11 November 2014.
76. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-78)**
["The MPG Illusion"](http://blogs.berkeley.edu/2013/06/03/the-mpg-illusion/). 3 June 2013. Retrieved 11 November 2014.
77. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-79)**
John M. Broder (25 May 2011). ["New Mileage Stickers Include Greenhouse Gas Data"](https://www.nytimes.com/2011/05/26/business/energy-environment/26label.html?_r=1&emc=eta1). *The New York Times*. Retrieved 26 May 2011.
78. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-80)**
["CAFE Overview: "What is the origin of CAFE?""](https://web.archive.org/web/20090203174614/http://www.nhtsa.dot.gov/portal/site/nhtsa/template.MAXIMIZE/menuitem.43ac99aefa80569eea57529cdba046a0/?javax.portlet.tpst=f2d14277f710b755fc08d51090008a0c_ws_MX&javax.portlet.prp_f2d14277f710b755fc08d51090008a0c_viewID=detail_view&javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken&itemID=199b8facdcfa4010VgnVCM1000002c567798RCRD&viewType=standard#6). NHTSA. Archived from [the original](http://www.nhtsa.dot.gov/portal/site/nhtsa/template.MAXIMIZE/menuitem.43ac99aefa80569eea57529cdba046a0/?javax.portlet.tpst=f2d14277f710b755fc08d51090008a0c_ws_MX&javax.portlet.prp_f2d14277f710b755fc08d51090008a0c_viewID=detail_view&javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken&itemID=199b8facdcfa4010VgnVCM1000002c567798RCRD&viewType=standard#6) on 3 February 2009. Retrieved 9 July 2008.
79. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-NYTApril18_81-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-NYTApril18_81-1)
[Tabuchi, Hiroko](https://en.wikipedia.org/wiki/Hiroko_Tabuchi "Hiroko Tabuchi") (2 April 2018). ["Calling car pollution standards 'too high,' EPA sets up fight with California"](https://www.nytimes.com/2018/04/02/climate/trump-auto-emissions-rules.html). *The New York Times*.
80. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ELQSept03_82-0)**
Giovinazzo, Christopher (September 2003). ["California's Global Warming Bill: Will Fuel Economy Preemption Curb California's Air Pollution Leadership"](https://scholarship.law.berkeley.edu/cgi/viewcontent.cgi?referer=https://www.google.com/&httpsredir=1&article=1735&context=elq). *Ecology Law Quarterly*. **30** (4): 901–902\.
81. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-NYTDec07_83-0)**
Tabuchi, Hiroko (19 December 2007). ["EPA Denies California's Emissions Waiver"](https://www.nytimes.com/2007/12/19/washington/20epa-web.html). *The New York Times*.
82. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-WaPoJan08_84-0)**
Richburg, Keith (3 January 2008). ["California Sues EPA Over Emissions Rules"](https://www.washingtonpost.com/wp-dyn/content/article/2008/01/02/AR2008010202833.html). *The Washington Post*.
83. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-GTMJune09_85-0)**
Wang, Ucilia (30 June 2009). ["EPA grants California emissions waiver"](https://www.greentechmedia.com/articles/read/epa-grants-california-emissions-waiver). *Greentech Media*.
84. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-86)**
["Obama Administration Finalizes Historic 54.5 MPG Fuel Efficiency Standards"](https://obamawhitehouse.archives.gov/the-press-office/2012/08/28/obama-administration-finalizes-historic-545-MPG-fuel-efficiency-standard). White House. 28 August 2012. Retrieved 28 November 2019.
85. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-87)**
Fraser, Laura (Winter 2012–2013). "Shifting Gears". *NRDC's OnEarth*. p. 63.
86. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-NYT2018_88-0)**
Tabuchi, Hiroko (5 April 2018). ["Quietly, Trump officials and California seek deal on emissions"](https://www.nytimes.com/2018/04/05/climate/trump-california-emissions.html). *The New York Times*.
87. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-89)**
Phillips, Anna M. (21 February 2019). ["Trump administration confirms it has ended fuel-economy talks with California"](https://www.latimes.com/politics/la-na-pol-california-fuel-economy-trump-20190220-story.html). *Los Angeles Times*. Retrieved 11 May 2019.
88. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-90)**
Associated Press (6 January 2021). ["For first time in 5 years, US gas mileage down, emissions up"](https://www.ocregister.com/2021/01/06/for-first-time-in-5-years-us-gas-mileage-down-emissions-up). *Orange County Register*. Retrieved 7 January 2021.
89. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-91)**
["Trump rollback of mileage standards guts climate change push"](https://news.yahoo.com/trump-rollback-mileage-standards-guts-151423701.html). *Yahoo News*. 31 March 2020. Retrieved 2 May 2023.
90. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-92)**
Kaufman, Alexander; D'Angelo, Chris (20 December 2021). ["EPA Reverses Trump's Fuel Mileage Rules On New Cars"](https://www.huffpost.com/entry/epa-reverses-trump-fuel-mileage-rules_n_61c0b34de4b061afe395ec7f). *HuffPost*. Retrieved 20 December 2021.
91. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-:0_93-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-:0_93-1)
Hilgers, Michael (2021). *Commercial Vehicle Technology: Fuel consumption and consumption optimization*. Wilfried Achenbach. Berlin. [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)")
[978-3-662-60841-8](https://en.wikipedia.org/wiki/Special:BookSources/978-3-662-60841-8 "Special:BookSources/978-3-662-60841-8")
. [OCLC](https://en.wikipedia.org/wiki/OCLC_\(identifier\) "OCLC (identifier)") [1237865094](https://search.worldcat.org/oclc/1237865094).
`{{cite book}}`: CS1 maint: location missing publisher ([link](https://en.wikipedia.org/wiki/Category:CS1_maint:_location_missing_publisher "Category:CS1 maint: location missing publisher"))
92. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA_CO2_est_94-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA_CO2_est_94-1)
["Emission Facts: Average Carbon Dioxide Emissions Resulting from Gasoline and Diesel Fuel"](https://web.archive.org/web/20090228190530/http://www.epa.gov/oms/climate/420f05001.htm). *Office of Transportation and Air Quality*. [United States Environmental Protection Agency](https://en.wikipedia.org/wiki/United_States_Environmental_Protection_Agency "United States Environmental Protection Agency"). February 2005. Archived from [the original](http://www.epa.gov/OMS/climate/420f05001.htm) on 28 February 2009. Retrieved 28 July 2009.
## External links
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=37 "Edit section: External links")\]
- [Real fuel consumption by user reports](https://www.auto-abc.eu/info/real-fuel-consumption)
- [Model Year 2014 Fuel Economy Guide](https://www.fueleconomy.gov/feg/pdfs/guides/FEG2014.pdf) , [U.S. Environmental Protection Agency](https://en.wikipedia.org/wiki/U.S._Environmental_Protection_Agency "U.S. Environmental Protection Agency") and [U.S. Department of Energy](https://en.wikipedia.org/wiki/U.S._Department_of_Energy "U.S. Department of Energy"), April 2014.
- [Fuel Efficiency in Electric, Hybrid and Petrol Cars – Model Year 2019](https://ecohungry.com/electric-and-petrol-cars-fuel-efficiency/)
- [Fuel Consumption Calculator Online](https://www.fuelcostcalculator.online/)
| [Authority control databases](https://en.wikipedia.org/wiki/Help:Authority_control "Help:Authority control") [](https://www.wikidata.org/wiki/Q931507#identifiers "Edit this at Wikidata") | |
|---|---|
| International | [GND](https://d-nb.info/gnd/4120612-5) |
| National | [United States](https://id.loc.gov/authorities/sh85010260) [France](https://catalogue.bnf.fr/ark:/12148/cb119595818) [BnF data](https://data.bnf.fr/ark:/12148/cb119595818) [Israel](https://www.nli.org.il/en/authorities/987007295838105171) |
| Other | [Yale LUX](https://lux.collections.yale.edu/view/concept/1f496c33-edde-41c7-af12-fc90221b4b9f) |
Retrieved from "<https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&oldid=1341142358>"
[Categories](https://en.wikipedia.org/wiki/Help:Category "Help:Category"):
- [Energy economics](https://en.wikipedia.org/wiki/Category:Energy_economics "Category:Energy economics")
- [Fuel technology](https://en.wikipedia.org/wiki/Category:Fuel_technology "Category:Fuel technology")
- [Green vehicles](https://en.wikipedia.org/wiki/Category:Green_vehicles "Category:Green vehicles")
- [Car costs](https://en.wikipedia.org/wiki/Category:Car_costs "Category:Car costs")
Hidden categories:
- [CS1 errors: missing periodical](https://en.wikipedia.org/wiki/Category:CS1_errors:_missing_periodical "Category:CS1 errors: missing periodical")
- [Webarchive template wayback links](https://en.wikipedia.org/wiki/Category:Webarchive_template_wayback_links "Category:Webarchive template wayback links")
- [Pages containing links to subscription-only content](https://en.wikipedia.org/wiki/Category:Pages_containing_links_to_subscription-only_content "Category:Pages containing links to subscription-only content")
- [CS1 maint: deprecated archival service](https://en.wikipedia.org/wiki/Category:CS1_maint:_deprecated_archival_service "Category:CS1 maint: deprecated archival service")
- [All articles with dead external links](https://en.wikipedia.org/wiki/Category:All_articles_with_dead_external_links "Category:All articles with dead external links")
- [Articles with dead external links from May 2024](https://en.wikipedia.org/wiki/Category:Articles_with_dead_external_links_from_May_2024 "Category:Articles with dead external links from May 2024")
- [Articles with permanently dead external links](https://en.wikipedia.org/wiki/Category:Articles_with_permanently_dead_external_links "Category:Articles with permanently dead external links")
- [CS1 maint: location missing publisher](https://en.wikipedia.org/wiki/Category:CS1_maint:_location_missing_publisher "Category:CS1 maint: location missing publisher")
- [Articles with short description](https://en.wikipedia.org/wiki/Category:Articles_with_short_description "Category:Articles with short description")
- [Short description is different from Wikidata](https://en.wikipedia.org/wiki/Category:Short_description_is_different_from_Wikidata "Category:Short description is different from Wikidata")
- [Use American English from January 2023](https://en.wikipedia.org/wiki/Category:Use_American_English_from_January_2023 "Category:Use American English from January 2023")
- [All Wikipedia articles written in American English](https://en.wikipedia.org/wiki/Category:All_Wikipedia_articles_written_in_American_English "Category:All Wikipedia articles written in American English")
- [Use dmy dates from January 2023](https://en.wikipedia.org/wiki/Category:Use_dmy_dates_from_January_2023 "Category:Use dmy dates from January 2023")
- [All articles with unsourced statements](https://en.wikipedia.org/wiki/Category:All_articles_with_unsourced_statements "Category:All articles with unsourced statements")
- [Articles with unsourced statements from November 2010](https://en.wikipedia.org/wiki/Category:Articles_with_unsourced_statements_from_November_2010 "Category:Articles with unsourced statements from November 2010")
- [Articles with unsourced statements from December 2024](https://en.wikipedia.org/wiki/Category:Articles_with_unsourced_statements_from_December_2024 "Category:Articles with unsourced statements from December 2024")
- [Wikipedia articles needing clarification from July 2019](https://en.wikipedia.org/wiki/Category:Wikipedia_articles_needing_clarification_from_July_2019 "Category:Wikipedia articles needing clarification from July 2019")
- [Articles needing additional references from November 2023](https://en.wikipedia.org/wiki/Category:Articles_needing_additional_references_from_November_2023 "Category:Articles needing additional references from November 2023")
- [All articles needing additional references](https://en.wikipedia.org/wiki/Category:All_articles_needing_additional_references "Category:All articles needing additional references")
- [Articles with unsourced statements from November 2009](https://en.wikipedia.org/wiki/Category:Articles_with_unsourced_statements_from_November_2009 "Category:Articles with unsourced statements from November 2009")
- [Articles with obsolete information from September 2018](https://en.wikipedia.org/wiki/Category:Articles_with_obsolete_information_from_September_2018 "Category:Articles with obsolete information from September 2018")
- [All Wikipedia articles in need of updating](https://en.wikipedia.org/wiki/Category:All_Wikipedia_articles_in_need_of_updating "Category:All Wikipedia articles in need of updating")
- [All articles with specifically marked weasel-worded phrases](https://en.wikipedia.org/wiki/Category:All_articles_with_specifically_marked_weasel-worded_phrases "Category:All articles with specifically marked weasel-worded phrases")
- [Articles with specifically marked weasel-worded phrases from November 2015](https://en.wikipedia.org/wiki/Category:Articles_with_specifically_marked_weasel-worded_phrases_from_November_2015 "Category:Articles with specifically marked weasel-worded phrases from November 2015")
- This page was last edited on 1 March 2026, at 18:19 (UTC).
- Text is available under the [Creative Commons Attribution-ShareAlike 4.0 License](https://en.wikipedia.org/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License "Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License"); additional terms may apply. By using this site, you agree to the [Terms of Use](https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use "foundation:Special:MyLanguage/Policy:Terms of Use") and [Privacy Policy](https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy "foundation:Special:MyLanguage/Policy:Privacy policy"). Wikipedia® is a registered trademark of the [Wikimedia Foundation, Inc.](https://wikimediafoundation.org/), a non-profit organization.
- [Privacy policy](https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy)
- [About Wikipedia](https://en.wikipedia.org/wiki/Wikipedia:About)
- [Disclaimers](https://en.wikipedia.org/wiki/Wikipedia:General_disclaimer)
- [Contact Wikipedia](https://en.wikipedia.org/wiki/Wikipedia:Contact_us)
- [Legal & safety contacts](https://foundation.wikimedia.org/wiki/Special:MyLanguage/Legal:Wikimedia_Foundation_Legal_and_Safety_Contact_Information)
- [Code of Conduct](https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct)
- [Developers](https://developer.wikimedia.org/)
- [Statistics](https://stats.wikimedia.org/#/en.wikipedia.org)
- [Cookie statement](https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement)
- [Mobile view](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&mobileaction=toggle_view_mobile)
- [](https://www.wikimedia.org/)
- [](https://www.mediawiki.org/)
Search
Toggle the table of contents
Fuel economy in automobiles
19 languages
[Add topic](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles) |
| Readable Markdown | [](https://en.wikipedia.org/wiki/File:CAFE_performance.svg)
New light-duty vehicle fuel economy by vehicle type from vehicle manufacturers in the United States, in miles per gallon (1975 - 2019)
[](https://en.wikipedia.org/wiki/File:2006_Honda_Airwave_fuel_efficiency_meter.jpg)
Fuel consumption monitor from a 2006 [Honda Airwave](https://en.wikipedia.org/wiki/Honda_Airwave "Honda Airwave"). The displayed fuel economy is 18.1 km/L (5.5 L/100 km; 43 mpg‑US).
[](https://en.wikipedia.org/wiki/File:Fuel_Economy,_1916.jpg)
A [Briggs and Stratton Flyer](https://en.wikipedia.org/wiki/Briggs_and_Stratton_Flyer "Briggs and Stratton Flyer") from 1916. Originally an experiment in creating a fuel-saving automobile in the United States, the vehicle weighed only 135 lb (61.2 kg) and was an adaptation of a small gasoline engine originally designed to power a bicycle.[\[1\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-1)
The **fuel economy** or **fuel efficiency** of an [automobile](https://en.wikipedia.org/wiki/Car "Car") relates to the [distance traveled](https://en.wikipedia.org/wiki/Distance_traveled "Distance traveled") by a vehicle and the amount of [fuel](https://en.wikipedia.org/wiki/Fuel "Fuel") consumed. It can be expressed in terms of the volume of fuel to travel a given distance, such as in **litres per 100 kilometres** (L/100 km), or through its inverse, the distance traveled per unit volume of fuel consumed, as in **kilometres per litre** (km/L) or **miles per gallon** (mpg). Since fuel economy of vehicles is a significant factor in [air pollution](https://en.wikipedia.org/wiki/Air_pollution "Air pollution"), the importation of [motor fuel](https://en.wikipedia.org/wiki/Motor_fuel "Motor fuel") can be a large part of a nation's [foreign trade](https://en.wikipedia.org/wiki/Foreign_trade "Foreign trade") and consumers frequently undervalue fuel efficiency, many countries impose requirements for fuel economy.
Different methods are used to approximate the actual performance of the vehicle. The energy in fuel is required to overcome various losses ([wind resistance](https://en.wikipedia.org/wiki/Wind_resistance "Wind resistance"), [tire drag](https://en.wikipedia.org/wiki/Tire_drag "Tire drag"), and others) encountered while propelling the vehicle, and in providing power to vehicle systems such as ignition or air conditioning. Various strategies can be employed to reduce losses at each of the conversions between the [chemical energy](https://en.wikipedia.org/wiki/Chemical_energy "Chemical energy") in the fuel and the [kinetic energy](https://en.wikipedia.org/wiki/Kinetic_energy "Kinetic energy") of the vehicle. Driver behavior can affect fuel economy; maneuvers such as sudden acceleration and heavy [braking](https://en.wikipedia.org/wiki/Braking "Braking") waste energy.
[Electric cars](https://en.wikipedia.org/wiki/Electric_car "Electric car") use [kilowatt-hours](https://en.wikipedia.org/wiki/Kilowatt-hours "Kilowatt-hours") of electricity per 100 kilometres (kWh/100km); in the U.S., an equivalence measure, such as [miles per gallon gasoline equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent "Miles per gallon gasoline equivalent") (US gallon) has been created to attempt to compare them.
## Quantities and units of measure
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=1 "Edit section: Quantities and units of measure")\]
[](https://en.wikipedia.org/wiki/File:Chart_MPG_to_L-100km_v2009-10-08.svg)
Conversion from mpg to L/100 km: blue - US [gallon](https://en.wikipedia.org/wiki/Gallon "Gallon"); red - UK gallon (imperial)
The fuel efficiency of motor vehicles can be expressed in multiple ways:
- **Fuel consumption** is the fuel used per unit distance; for example, **[litres](https://en.wikipedia.org/wiki/Litre "Litre") per 100 [kilometres](https://en.wikipedia.org/wiki/Kilometre "Kilometre") (L/100 km)**. The **lower** the value, the more economic a vehicle is; this is the measure generally used across [Europe](https://en.wikipedia.org/wiki/Europe "Europe") (except the UK, Denmark and The Netherlands - see below), [Africa](https://en.wikipedia.org/wiki/Africa "Africa"), [New Zealand](https://en.wikipedia.org/wiki/New_Zealand "New Zealand"), [Australia](https://en.wikipedia.org/wiki/Australia "Australia"), and [Canada](https://en.wikipedia.org/wiki/Canada "Canada"), [Uruguay](https://en.wikipedia.org/wiki/Uruguay "Uruguay"), [Paraguay](https://en.wikipedia.org/wiki/Paraguay "Paraguay"), [Guatemala](https://en.wikipedia.org/wiki/Guatemala "Guatemala"), [Colombia](https://en.wikipedia.org/wiki/Colombia "Colombia"), [China](https://en.wikipedia.org/wiki/China "China"), and [Madagascar](https://en.wikipedia.org/wiki/Madagascar "Madagascar"), and in the former [CIS](https://en.wikipedia.org/wiki/Commonwealth_of_Independent_States "Commonwealth of Independent States") states. \[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\],
- **Fuel economy** is the distance travelled per unit volume of fuel used; for example, **kilometres per litre (km/L)** or **[miles](https://en.wikipedia.org/wiki/Mile "Mile") per [gallon](https://en.wikipedia.org/wiki/Gallon "Gallon") (MPG)**. The **higher** the value, the more economic a vehicle is (the more distance it can travel with a certain volume of fuel). This measure is popular in the US and the UK (mpg), but in Europe, India, Japan, South Korea the metric unit *km/L* is used instead.
The formula for converting to miles per US gallon (3.7854 L) from L/100 km is , where  is value of L/100 km. For miles per Imperial gallon (4.5461 L) the formula is .
Europe now uses the [WLTP](https://en.wikipedia.org/wiki/Worldwide_Harmonised_Light_Vehicles_Test_Procedure "Worldwide Harmonised Light Vehicles Test Procedure") standard to compare the fuel economy of all new vehicles.
Fuel economy can be expressed in two ways:
Units of fuel per fixed distance
Generally expressed in liters per 100 kilometers (L/100 km), used in most European countries, Canada, China, South Africa, Australia and New Zealand. Irish law allows for the use of miles per imperial [gallon](https://en.wikipedia.org/wiki/Gallon "Gallon"), alongside liters per 100 kilometers.[\[2\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-2) Liters per 100 kilometers may be used alongside miles per imperial [gallon](https://en.wikipedia.org/wiki/Gallon "Gallon") in the UK. The [window sticker](https://en.wikipedia.org/wiki/Monroney_sticker "Monroney sticker") on new US cars displays the vehicle's fuel consumption in US gallons per 100 miles, in addition to the traditional mpg number.[\[3\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-3) A lower number means more efficient, while a higher number means less efficient.
Units of distance per fixed fuel unit
Miles per [gallon](https://en.wikipedia.org/wiki/Gallon "Gallon") (mpg) are commonly used in the United States, the United Kingdom, and Canada (alongside L/100 km). Kilometers per liter (km/L) are more commonly used elsewhere in the Americas, Asia, parts of Africa and Oceania. In the [Levant](https://en.wikipedia.org/wiki/Levant "Levant") km/20 L is used, known as kilometers per *[tanaka](https://en.wiktionary.org/wiki/%D8%AA%D9%86%D9%83%D8%A9 "wikt:تنكة")*, a [metal container](https://en.wikipedia.org/wiki/Jerrycan "Jerrycan") which has a volume of twenty liters.\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\] When mpg is used, it is necessary to identify the type of gallon: the imperial gallon is 4.54609 liters, and the U.S. gallon is 3.785 liters. When using a measure expressed as distance per fuel unit, a higher number means more efficient, while a lower number means less efficient.
**Conversions of units:**
[](https://en.wikipedia.org/wiki/File:1975-_US_vehicle_production_share,_by_vehicle_type.svg)
Trucks' share of US vehicles produced, has tripled since 1975. Though vehicle fuel efficiency has increased within each category, the overall trend toward less efficient types of vehicles has offset some of the benefits of greater fuel economy and reduction of carbon dioxide emissions.[\[4\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA_AutomotiveTrends_202212-4) Without the shift towards SUVs, energy use per unit distance could have fallen 30% more than it did from 2010 to 2022.[\[5\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-GlobalFuelEfficInit_202311-5)
While the [thermal efficiency](https://en.wikipedia.org/wiki/Thermal_efficiency "Thermal efficiency") (mechanical output to chemical energy in fuel) of petroleum [engines](https://en.wikipedia.org/wiki/Internal_combustion_engine "Internal combustion engine") has increased since the beginning of the [automotive era](https://en.wikipedia.org/wiki/History_of_the_automobile "History of the automobile"), this is not the only factor in fuel economy. The design of automobile as a whole and usage pattern affects the fuel economy. Published fuel economy is subject to variation between jurisdiction due to variations in testing protocols.
One of the first studies to determine fuel economy in the United States was the [Mobil Economy Run](https://en.wikipedia.org/wiki/Mobil_Economy_Run "Mobil Economy Run"), which was an event that took place every year from 1936 (except during [World War II](https://en.wikipedia.org/wiki/World_War_II "World War II")) to 1968. It was designed to provide real, efficient [fuel efficiency](https://en.wikipedia.org/wiki/Fuel_efficiency "Fuel efficiency") numbers during a coast-to-coast test on real roads and with regular traffic and weather conditions. The [Mobil](https://en.wikipedia.org/wiki/Mobil "Mobil") Oil Corporation sponsored it and the [United States Auto Club](https://en.wikipedia.org/wiki/United_States_Auto_Club "United States Auto Club") (USAC) sanctioned and operated the run. In more recent studies, the average fuel economy for new passenger car in the United States improved from 17 mpg (13.8 L/100 km) in 1978 to 22 mpg (10.7 L/100 km) in 1982.[\[6\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-6) The average[\[a\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-7) fuel economy for new 2020 model year cars, light trucks and SUVs in the United States was 25.4 miles per US gallon (9.3 L/100 km).[\[7\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-8) 2019 model year cars (ex. EVs) classified as "midsize" by the US EPA ranged from 12 to 56 mpgUS (20 to 4.2 L/100 km)[\[8\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-2019_epa_BestandWorst-9) However, due to environmental concerns caused by CO2 emissions, new EU regulations are being introduced to reduce the average emissions of cars sold beginning in 2012, to 130 g/km of CO2, equivalent to 4.5 L/100 km (52 mpgUS, 63 mpgimp) for a diesel-fueled car, and 5.0 L/100 km (47 mpgUS, 56 mpgimp) for a gasoline (petrol)-fueled car.[\[9\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-10)
The average consumption across the fleet is not immediately affected by the *new vehicle* fuel economy: for example, Australia's car fleet average in 2004 was 11.5 L/100 km (20.5 mpgUS),[\[10\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-11) compared with the average new car consumption in the same year of 9.3 L/100 km (25.3 mpgUS)[\[11\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-pew-12)
### Speed and fuel economy studies
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=3 "Edit section: Speed and fuel economy studies")\]
[](https://en.wikipedia.org/wiki/File:Fuel_economy_vs_speed_1997.png)
1997 fuel economy statistics for various US models
Fuel economy at steady speeds with selected vehicles was studied in 2010. The most recent study[\[12\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ornl-13) indicates greater fuel efficiency at higher speeds than earlier studies; for example, some vehicles achieve better fuel economy at 100 km/h (62 mph) rather than at 70 km/h (43 mph),[\[12\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ornl-13) although not their best economy, such as the 1994 [Oldsmobile Cutlass Ciera](https://en.wikipedia.org/wiki/Oldsmobile_Cutlass_Ciera "Oldsmobile Cutlass Ciera") with the [LN2](https://en.wikipedia.org/wiki/General_Motors_122_engine#LN2 "General Motors 122 engine") 2.2L engine, which has its best economy at 90 km/h (56 mph) (8.1 L/100 km (29 mpg‑US)), and gets better economy at 105 km/h (65 mph) than at 72 km/h (45 mph) (9.4 L/100 km (25 mpg‑US) vs 22 mpg‑US (11 L/100 km)). The proportion of driving on [high speed roadways](https://en.wikipedia.org/wiki/Highway_safety#Motorway "Highway safety") varies from 4% in Ireland to 41% in the Netherlands.
When the US [National Maximum Speed Law](https://en.wikipedia.org/wiki/National_Maximum_Speed_Law "National Maximum Speed Law")'s 55 mph (89 km/h) speed limit was mandated from 1974 to 1995, there were complaints that fuel economy could decrease instead of increase. The 1997 Toyota Celica got better fuel-efficiency at 105 km/h (65 mph) than it did at 65 km/h (40 mph) (5.41 L/100 km (43.5 mpg‑US) vs 5.53 L/100 km (42.5 mpg‑US)), although even better at 60 mph (97 km/h) than at 65 mph (105 km/h) (48.4 mpg‑US (4.86 L/100 km) vs 43.5 mpg‑US (5.41 L/100 km)), and its best economy (52.6 mpg‑US (4.47 L/100 km)) at only 25 mph (40 km/h). Other vehicles tested had from 1.4 to 20.2% better fuel-efficiency at 90 km/h (56 mph) vs. 105 km/h (65 mph). Their best economy was reached at speeds of 40 to 90 km/h (25 to 56 mph) (see graph).[\[12\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ornl-13)
Officials hoped that the 55 mph (89 km/h) limit, combined with a ban on ornamental lighting, no gasoline sales on Sunday, and a 15% cut in gasoline production, would reduce total gasoline consumption by 200,000 [barrels](https://en.wikipedia.org/wiki/Oil_barrel "Oil barrel") a day, representing a 2.2% drop from annualized 1973 gasoline consumption levels.[\[13\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-14)[\[b\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-16) This was partly based on a belief that cars achieve maximum efficiency between 40 and 50 mph (65 and 80 km/h) and that trucks and buses were most efficient at 55 mph (89 km/h).[\[15\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-17)
In 1998, the U.S. [Transportation Research Board](https://en.wikipedia.org/wiki/Transportation_Research_Board "Transportation Research Board") footnoted an estimate that the 1974 National Maximum Speed Limit (NMSL) reduced fuel consumption by 0.2 to 1.0 percent.[\[16\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-18) Rural interstates, the roads most visibly affected by the NMSL, accounted for 9.5% of the U.S' vehicle-miles-traveled in 1973,[\[17\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-19) but such free-flowing roads typically provide more fuel-efficient travel than conventional roads.[\[18\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-greenvehicleguide.gov.au-20) [\[19\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-lexus.de-21) [\[20\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-fueleconomy.gov-22)
### Discussion of statistics
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=4 "Edit section: Discussion of statistics")\]
A reasonably modern European [supermini](https://en.wikipedia.org/wiki/Supermini_car "Supermini car") and many mid-size cars, including station wagons, may manage [motorway](https://en.wikipedia.org/wiki/Motorway "Motorway") travel at 5 L/100 km (47 mpg‑US; 56 mpg‑imp) or 6.5 L/100 km (36 mpg‑US; 43 mpg‑imp), with [carbon dioxide](https://en.wikipedia.org/wiki/Carbon_dioxide "Carbon dioxide") emissions of around 140 g/km.
An average [North American](https://en.wikipedia.org/wiki/North_America "North America") [mid-size car](https://en.wikipedia.org/wiki/Mid-size_car "Mid-size car") averages 21 mpg‑US (11 L/100 km; 25 mpg‑imp)) city, 27 mpg‑US (8.7 L/100 km; 32 mpg‑imp)) highway; a [full-size](https://en.wikipedia.org/wiki/Full-size_car "Full-size car") [SUV](https://en.wikipedia.org/wiki/SUV "SUV") usually averages 13 mpg‑US (18 L/100 km; 16 mpg‑imp) city and 16 mpg‑US (15 L/100 km; 19 mpg‑imp) highway. [Pickup trucks](https://en.wikipedia.org/wiki/Pickup_truck "Pickup truck") vary considerably; whereas a 4 cylinder-engined light pickup can achieve 28 mpg‑US (8.4 L/100 km; 34 mpg‑imp), a [V8](https://en.wikipedia.org/wiki/V8_engine "V8 engine") full-size pickup with extended cabin averages13 mpg‑US (18 L/100 km; 16 mpg‑imp) city and 15 mpg‑US (16 L/100 km; 18 mpg‑imp) highway.
The average fuel economy for all vehicles on the road is higher in Europe than the United States because the higher cost of fuel changes [consumer behaviour](https://en.wikipedia.org/wiki/Consumer_behaviour "Consumer behaviour"). In the UK, an imperial gallon of fuel cost US\$6.06 in 2005. The average cost in the United States was US\$2.61 for a US gallon.[\[21\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-23)
European-built cars are generally more fuel-efficient than US vehicles. While Europe has many highly efficiency diesel cars, European gasoline/petrol vehicles are on average also more efficient than gasoline-powered vehicles in the USA. Most European vehicles cited in the CSI study run on diesel engines, which tend to achieve greater fuel efficiency than gasoline/petrol engines. Selling those cars in the United States is difficult because of emission standards, notes Walter McManus, a fuel economy expert at the University of Michigan Transportation Research Institute. "For the most part, European diesels don’t meet U.S. emission standards", McManus said in 2007. Another reason why many European models are not sold in the United States is that labor unions object to having the big 3 import any new foreign built models regardless of fuel economy while laying off workers at home.[\[22\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-24)
An example of European cars' capabilities of fuel economy is the [microcar](https://en.wikipedia.org/wiki/Microcar "Microcar") *[Smart Fortwo](https://en.wikipedia.org/wiki/Smart_Fortwo "Smart Fortwo")* cdi, which can achieve up to 3.4 L/100 km (83 mpg‑imp; 69 mpg‑US) using a [turbocharged](https://en.wikipedia.org/wiki/Turbocharger "Turbocharger") three-cylinder 30 kW (40 hp) Diesel engine. The Fortwo is produced by [Daimler AG](https://en.wikipedia.org/wiki/Daimler_AG "Daimler AG") and is only sold by one company in the United States. Furthermore, the world record in fuel economy of production cars is held by the [Volkswagen Group](https://en.wikipedia.org/wiki/Volkswagen_Group "Volkswagen Group"), with special production models (labeled "3L") of the [Volkswagen Lupo](https://en.wikipedia.org/wiki/Volkswagen_Lupo#Lupo_3L "Volkswagen Lupo") and the [Audi A2](https://en.wikipedia.org/wiki/Audi_A2#1.2_TDI_"3L" "Audi A2"), consuming as little as 3 L/100 km (94 mpg‑imp; 78 mpg‑US).[\[23\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-25)\[*[clarification needed](https://en.wikipedia.org/wiki/Wikipedia:Please_clarify "Wikipedia:Please clarify")*\]
[Diesel engines](https://en.wikipedia.org/wiki/Diesel_engine "Diesel engine") generally achieve greater fuel efficiency than petrol (gasoline) engines. Passenger car diesel engines have [energy efficiency](https://en.wikipedia.org/wiki/Energy_conversion_efficiency "Energy conversion efficiency") of up to 41% but more typically 30%, and petrol engines of up to 37.3%, but more typically 20%. A common margin is 25% more efficiency for a turbodiesel.
For example, the current model Skoda Octavia, using Volkswagen engines, has a combined European fuel efficiency of 5.7 L/100 km (50 mpg‑imp; 41 mpg‑US) for the 78 kW (105 hp) petrol engine and 4.5 L/100 km (63 mpg‑imp; 52 mpg‑US) for the 78 kW (105 hp) heavier diesel engine vehicle. The higher compression ratio raises the energy efficiency, but diesel fuel also contains approximately 10% more energy per unit volume than gasoline/petrol which contributes to the reduced fuel consumption for a given power output.
In 2002, the United States had 85,174,776 trucks, and averaged 13.5 mpg‑US (17.4 L/100 km; 16.2 mpg‑imp). Large trucks, over 33,000 lb (15,000 kg), averaged 5.7 mpg‑US (41 L/100 km; 6.8 mpg‑imp).[\[24\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-26)
| [GVWR](https://en.wikipedia.org/wiki/Gross_vehicle_weight_rating "Gross vehicle weight rating") lbs | Number | Percentage | Average miles per truck | fuel economy | Percentage of fuel use |
|---|---|---|---|---|---|
| 6,000 lbs and less | 51,941,389 | 61\.00% | 11,882 | 17\.6 | 42\.70% |
| 6,001 – 10,000 lbs | 28,041,234 | 32\.90% | 12,684 | 14\.3 | 30\.50% |
| Light truck subtotal | 79,982,623 | 93\.90% | 12,163 | 16\.2 | 73\.20% |
| 10,001 – 14,000 lbs | 691,342 | 0\.80% | 14,094 | 10\.5 | 1\.10% |
| 14,001 – 16,000 lbs | 290,980 | 0\.30% | 15,441 | 8\.5 | 0\.50% |
| 16,001 – 19,500 lbs | 166,472 | 0\.20% | 11,645 | 7\.9 | 0\.30% |
| 19,501 – 26,000 lbs | 1,709,574 | 2\.00% | 12,671 | 7 | 3\.20% |
| Medium truck subtotal | 2,858,368 | 3\.40% | 13,237 | 8 | 5\.20% |
| 26,001 – 33,000 lbs | 179,790 | 0\.20% | 30,708 | 6\.4 | 0\.90% |
| 33,001 lbs and up | 2,153,996 | 2\.50% | 45,739 | 5\.7 | 20\.70% |
| Heavy truck subtotal | 2,333,786 | 2\.70% | 44,581 | 5\.8 | 21\.60% |
| Total | 85,174,776 | 100\.00% | 13,088 | 13\.5 | 100\.00% |
The average economy of automobiles in the United States in 2002 was 22.0 miles per US gallon (10.7 L/100 km; 26.4 mpg‑imp). By 2010 this had increased to 23.0 miles per US gallon (10.2 L/100 km; 27.6 mpg‑imp). Average fuel economy in the United States gradually declined until 1973, when it reached a low of 13.4 miles per US gallon (17.6 L/100 km; 16.1 mpg‑imp) and gradually has increased since, as a result of higher fuel cost.[\[25\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-27) A study indicates that a 10% increase in gas prices will eventually produce a 2.04% increase in fuel economy.[\[26\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-28) One method by car makers to increase fuel efficiency is [lightweighting](https://en.wikipedia.org/wiki/Lightweighting "Lightweighting") in which lighter-weight materials are substituted in for improved engine performance and handling.[\[27\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-twsMercuryNews-29)
### Differences in testing standards
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=5 "Edit section: Differences in testing standards")\]
Identical vehicles can have varying fuel consumption figures listed depending upon the testing methods of the jurisdiction.[\[28\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-30)
Lexus [IS 250](https://en.wikipedia.org/wiki/Lexus_IS#Second_generation_\(2006%E2%80%93present\) "Lexus IS") – petrol 2.5 L *[4GR-FSE](https://en.wikipedia.org/wiki/Toyota_GR_engine#4GR-FSE "Toyota GR engine")* [V6](https://en.wikipedia.org/wiki/V6 "V6"), 204 hp (153 kW), 6 speed automatic, rear wheel drive
- **Australia** (L/100 km) – 'combined' 9.1, 'urban' 12.7, 'extra-urban' 7.0[\[18\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-greenvehicleguide.gov.au-20)
- **Canada** (L/100 km) – 'combined' 9.6, 'city' 11.1, 'highway' 7.8[\[29\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-31)
- **European Union** (L/100 km) – 'combined' 8.9, 'urban' 12.5, 'extra-urban' 6.9[\[19\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-lexus.de-21)
- **United States** (L/100 km) – 'combined' 9.8, 'city' 11.2, 'highway' 8.1[\[20\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-fueleconomy.gov-22)
## Energy considerations
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=6 "Edit section: Energy considerations")\]
Since the total force opposing the vehicle's motion (at constant speed) multiplied by the distance through which the vehicle travels represents the work that the vehicle's engine must perform, the study of fuel economy (the amount of energy consumed per unit of distance traveled) requires a detailed analysis of the forces that oppose a vehicle's motion. In terms of physics, Force = rate at which the amount of work generated (energy delivered) varies with the distance traveled, or:
Note: The amount of work generated by the vehicle's power source (energy delivered by the engine) would be exactly proportional to the amount of fuel energy consumed by the engine if the engine's efficiency is the same regardless of power output, but this is not necessarily the case due to the operating characteristics of the internal combustion engine.
For a vehicle whose source of power is a heat engine (an engine that uses heat to perform useful work), the amount of fuel energy that a vehicle consumes per unit of distance (level road) depends upon:
1. The [thermodynamic efficiency of the heat engine](https://en.wikipedia.org/wiki/Energy_efficiency_of_internal_combustion_engines "Energy efficiency of internal combustion engines");
2. Frictional losses within the [drivetrain](https://en.wikipedia.org/wiki/Drivetrain "Drivetrain");
3. [Rolling resistance](https://en.wikipedia.org/wiki/Rolling_resistance "Rolling resistance") within the wheels and between the road and the wheels;
4. Non-motive subsystems powered by the engine, such as [air conditioning](https://en.wikipedia.org/wiki/Automobile_air_conditioning "Automobile air conditioning"), [engine cooling](https://en.wikipedia.org/wiki/Internal_combustion_engine_cooling "Internal combustion engine cooling"), and the [alternator](https://en.wikipedia.org/wiki/Alternator_\(automotive\) "Alternator (automotive)");
5. [Aerodynamic drag](https://en.wikipedia.org/wiki/Drag_\(physics\) "Drag (physics)") from moving through air;
6. Energy converted by [frictional brakes](https://en.wikipedia.org/wiki/Friction_brake "Friction brake") into waste heat, or losses from [regenerative braking](https://en.wikipedia.org/wiki/Regenerative_brake "Regenerative brake") in [hybrid vehicles](https://en.wikipedia.org/wiki/Hybrid_vehicle "Hybrid vehicle");
7. Fuel consumed while the engine is not providing power but still running, such as while [idling](https://en.wikipedia.org/wiki/Idle_\(engine\) "Idle (engine)"), minus the subsystem loads.[\[30\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-32)
[](https://en.wikipedia.org/wiki/File:Energy_flows_in_car.svg)
Energy dissipation in city and highway driving for a mid-size gasoline-powered car
Ideally, a car traveling at a constant velocity on level ground in a vacuum with frictionless wheels could travel at any speed without consuming any energy beyond what is needed to get the car up to speed. Less ideally, any vehicle must expend energy on overcoming road load forces, which consist of aerodynamic drag, tire rolling resistance, and inertial energy that is lost when the vehicle is decelerated by friction brakes. With ideal [regenerative braking](https://en.wikipedia.org/wiki/Regenerative_braking "Regenerative braking"), the inertial energy could be completely recovered, the only options for reducing aerodynamic drag or rolling resistance other than optimizing the vehicle's shape and the tire design. Road load energy or the energy demanded at the wheels, can be calculated by evaluating the vehicle equation of motion over a specific driving cycle.[\[31\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-33) The vehicle powertrain must then provide this minimum energy to move the vehicle and will lose a large amount of additional energy in the process of converting fuel energy into work and transmitting it to the wheels. Overall, the sources of energy loss in moving a vehicle may be summarized as follows:
- [Engine efficiency](https://en.wikipedia.org/wiki/Engine_efficiency "Engine efficiency") (20–30%), which varies with engine type, the mass of the automobile and its load, and engine speed (usually measured in [RPM](https://en.wikipedia.org/wiki/Revolutions_per_minute "Revolutions per minute")).
- [Aerodynamic drag](https://en.wikipedia.org/wiki/Aerodynamic_drag "Aerodynamic drag") force, which increases roughly by the [square of the car's speed](https://en.wikipedia.org/wiki/Drag_equation "Drag equation"), but notes that [drag power goes by the cube of the car's speed](https://en.wikipedia.org/wiki/Drag_power "Drag power").
- [Rolling friction](https://en.wikipedia.org/wiki/Rolling_friction "Rolling friction").
- Braking, although [regenerative braking](https://en.wikipedia.org/wiki/Regenerative_braking "Regenerative braking") captures some of the energy that would otherwise be lost.
- Losses in the [transmission](https://en.wikipedia.org/wiki/Transmission_\(mechanics\) "Transmission (mechanics)"). [Manual transmissions](https://en.wikipedia.org/wiki/Manual_transmission "Manual transmission") can be up to 94% efficient whereas older [automatic transmissions](https://en.wikipedia.org/wiki/Automatic_transmission "Automatic transmission") may be as low as 70% efficient[\[32\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-34) [Automated manual transmissions](https://en.wikipedia.org/wiki/Automated_manual_transmission "Automated manual transmission"), which have the same mechanical internals as conventional [manual transmissions](https://en.wikipedia.org/wiki/Manual_transmission "Manual transmission"), will give the same efficiency as a pure manual gearbox plus the added bonus of intelligence selecting optimal shifting points, and/or automated clutch control but manual shifting, as with older [semi-automatic transmissions](https://en.wikipedia.org/wiki/Semi-automatic_transmission "Semi-automatic transmission").
- Air conditioning. The power required for the engine to turn the compressor decreases the fuel-efficiency, though only when in use. This may be offset by the reduced drag of the vehicle compared with driving with the windows down. The efficiency of AC systems gradually deteriorates due to dirty filters etc.; regular maintenance prevents this. The extra mass of the air conditioning system will cause a slight increase in fuel consumption.
- Power steering. The older hydraulic power steering systems are powered by a hydraulic pump constantly engaged to the engine. Power assistance required for steering is inversely proportional to the vehicle speed so the constant load on the engine from a hydraulic pump reduces fuel efficiency. More modern designs improve fuel efficiency by only activating the power assistance when needed; this is done by using either direct electrical power steering assistance or an electrically powered hydraulic pump.
- Cooling. The older cooling systems used a constantly engaged mechanical fan to draw air through the radiator at a rate directly related to the engine speed. This constant load reduces efficiency. More modern systems use electrical fans to draw additional air through the radiator when extra cooling is required.
- Electrical systems. Headlights, battery charging, active suspension, circulating fans, defrosters, media systems, speakers, and other electronics can also significantly increase fuel consumption, as the energy to power these devices causes an increased load on the alternator. Since alternators are commonly only 40–60% efficient, the added load from electronics on the engine can be as high as 3 horsepower (2.2 kW) at any speed including idle. In the FTP 75 cycle test, a 200-watt load on the alternator reduces fuel efficiency by 1.7 mpg‑US (140 L/100 km; 2.0 mpg‑imp).[\[33\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ieee-35) Headlights, for example, consume 110 watts on low and up to 240 watts on high. These electrical loads can cause much of the discrepancy between real-world and EPA tests, which only include the electrical loads required to run the engine and basic climate control.
- Standby. The energy is needed to keep the engine running while it is not providing power to the wheels, i.e., when stopped, coasting or braking.
Fuel-efficiency decreases from electrical loads are most pronounced at lower speeds because most electrical loads are constant while engine load increases with speed. So at a lower speed, a higher proportion of [engine power](https://en.wikipedia.org/wiki/Engine_power "Engine power") is used by electrical loads. Hybrid cars see the greatest effect on fuel-efficiency from electrical loads because of this proportional effect.
### Fuel economy-boosting technologies
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=7 "Edit section: Fuel economy-boosting technologies")\]
#### Engine-specific technology
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=8 "Edit section: Engine-specific technology")\]
| Type | Technology | Explanation | Inventor | Notes |
|---|---|---|---|---|
| Engine cycle | Replacing petrol engines with diesel engines | Reduces brake specific fuel consumption at lower RPM | Herbert Akroyd Stuart | |
| Engine combustion strategies | Electronic control of the cooling system | Optimizes engine running temperature | | |
| | Stratified Charge combustion | Injects fuel into cylinder just before ignition, increasing compression ratio | | For use in petrol engines |
| | Lean burn combustion | Increases air/fuel ratio to reduce throttling losses | Chrysler | <https://www.youtube.com/watch?v=KnNX6gtDyhg> |
| | Cooled [exhaust gas recirculation](https://en.wikipedia.org/wiki/Exhaust_gas_recirculation "Exhaust gas recirculation") (petrol) | Reduces throttling losses, heat rejection, chemical dissociation, and specific heat ratio | | |
| | Cooled exhaust gas recirculation (diesel) | Lowers peak combustion temperatures | | |
| | [Atkinson cycle](https://en.wikipedia.org/wiki/Atkinson_cycle "Atkinson cycle") | Lengthens power stroke to achieve greater thermal efficiency | James Atkinson | [](https://en.wikipedia.org/wiki/File:Atkinson_Gas_Engine_Animated.gif) Atkinson cycle |
| | [Variable valve timing](https://en.wikipedia.org/wiki/Variable_valve_timing "Variable valve timing") and [variable valve lift](https://en.wikipedia.org/wiki/Variable_valve_lift "Variable valve lift") | Alters valve lift timing and height for precise control over intake and exhaust | | William Howe and William Williams ([Robert Stephenson and Company](https://en.wikipedia.org/wiki/Robert_Stephenson_and_Company "Robert Stephenson and Company")) invented the first [variable timing valve](https://en.wikipedia.org/wiki/Stephenson_valve_gear "Stephenson valve gear") |
| | Variable geometry turbocharging | Optimizes airflow with adjustable vanes to regulate turbocharger's air intake and eliminate turbo lag | Garrett ([Honeywell](https://en.wikipedia.org/wiki/Honeywell_Turbo_Technologies "Honeywell Turbo Technologies")) | [](https://en.wikipedia.org/wiki/File:VNT_Vanes_Open.jpg) VNT Vanes Open |
| | Twincharging | Combines a supercharger with a turbocharger to eliminate turbo lag | Lancia | For use in small-displacement engines |
| | Gasoline direct injection (GDI) engines | Allows for stratified fuel charge and ultra-lean burn | Leon Levavasseur | |
| | [Turbocharged Direct Injection](https://en.wikipedia.org/wiki/Turbocharged_Direct_Injection "Turbocharged Direct Injection") diesel engines | Combines direct injection with a turbocharger | Volkswagen | |
| | Common rail direct injection | Increases injection pressure | Robert Huber | |
| | Piezoelectric diesel injectors | Uses multiple injections per engine cycle for increased precision | | |
| | Cylinder management | Shuts off individual cylinders when their power output is not needed | | |
| | HCCI (Homogeneous Charge Compression Ignition) combustion | Allows leaner and higher compression burn | | <https://www.youtube.com/watch?v=B8CnYljXAS0> |
| | [Scuderi engine](https://en.wikipedia.org/wiki/Scuderi_engine "Scuderi engine") | Eliminates recompression losses | Carmelo J. Scuderi | [](https://en.wikipedia.org/wiki/File:Scuderi_Split_Cycle_Engine_-_Cycle.gif) Scuderi engine |
| | Compound engines (6-stroke engine or turbo-compound engine) | Recovers exhaust energy | | |
| | Two-stroke diesel engines | Increases power to weight ratio | Charles F. Kettering | |
| | High-efficiency gas turbine engines | Increases power to weight ratio | | |
| | Turbosteamer | Uses heat from the engine to spin a mini turbine to generate power | Raymond Freymann (BMW) | |
| | Stirling hybrid battery vehicle | Increases thermal efficiency | Still largely theoretical, although prototypes have been produced by Dean Kamen | |
| | Time-optimized piston path | Captures energy from gases in the cylinders at their highest temperatures | | |
| Engine internal losses | Downsized engines with a supercharger or a turbocharger | Reduces engine displacement while maintaining sufficient torque | Saab, starting with the 99 in 1978. | [](https://en.wikipedia.org/wiki/File:2014-Global-Turbo-Forecast.png) 2014-Global-Turbo-Forecast |
| | Lower-friction lubricants (engine oil, transmission fluid, axle fluid) | Reduces energy lost to friction | | |
| | Lower viscosity engine oils | Reduces hydrodynamic friction and energy required to circulate | | |
| | Variable displacement oil pump | Avoids excessive flow rate at high engine speed | | |
| | Electrifying engine accessories (water pump, power steering pump, and air conditioner compressor) | Sends more engine power to the transmission or reduces the fuel required for the same traction power | | |
| | Roller type cam, low friction coating on piston skirt and optimizing load-bearing surface, e.g. camshaft bearing and connective rods. | Reduces engine frictions | | |
| Engine running conditions | Coolant additives | Increases the thermal efficiency of the cooling system | | |
| | Increasing the number of gearbox ratios in manual gearboxes | Lowers the engine rpm at cruise | | |
| | Reducing the volume of water-based cooling systems | Engine reaches its efficient operating temperature more quickly | | |
| | [Start-stop system](https://en.wikipedia.org/wiki/Start-stop_system "Start-stop system") | Automatically shuts off engine when vehicle is stopped, reducing idle time | | |
| | Downsized engines with an electric drive system and battery | Avoids low-efficiency idle and power conditions | | |
#### Other vehicle technologies
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=9 "Edit section: Other vehicle technologies")\]
| Type | Technology | Explanation | Inventor | Notes |
|---|---|---|---|---|
| Transmission losses | Continuously variable transmission (CVT) | Enables engine to run at its most efficient RPM | | For use in automatic gearboxes |
| | Locking torque converters in automatic transmissions | Reduces slip and power losses in the converter | | |
| Rolling resistance | Lighter construction materials (aluminum, fiberglass, plastic, high-strength steel, and carbon fiber) | Reduces vehicle weight | | |
| | Increasing tire pressure | Lowers tire deformation under weight | | |
| | Replacing tires with low rolling resistance (LRR) models | Lowers rolling resistance[\[34\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-36) | | |
| Series parallel hybrid | Using an electric motor for the base power and an IC engine for assists and boosts, when needed | Decreases fuel consumption by running the petrol engine only when needed, in this way also environmentally friendly. | TRW | |
| Energy saving | Lighter materials for moving parts (pistons, crankshaft, gears, and alloy wheels) | Reduces the energy required to move parts | | |
| | [Regenerative braking](https://en.wikipedia.org/wiki/Regenerative_braking "Regenerative braking") | Captures kinetic energy while braking | Louis Antoine Kriéger | For use in hybrid or electric vehicles |
| | Recapturing waste heat from the exhaust system | Converts heat energy into electricity using [thermoelectric cooling](https://en.wikipedia.org/wiki/Thermoelectric_cooling "Thermoelectric cooling") | [Jean Charles Athanase Peltier](https://en.wikipedia.org/wiki/Jean_Charles_Athanase_Peltier "Jean Charles Athanase Peltier") | |
| | Regenerative shock absorbers | Recaptures wasted energy in the vehicle suspension[\[35\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-37) | Levant Power | |
| Traffic management | Active highway management | Matches speed limits and vehicles allowed to join motorways with traffic density to maintain traffic throughput | | |
| | Vehicle electronic control systems that automatically maintain distances between vehicles on motorways | Reduces ripple back braking and consequent re-acceleration | | |
#### Future technologies
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=10 "Edit section: Future technologies")\]
Technologies that may improve fuel efficiency, but are not yet on the market, include:
- [HCCI](https://en.wikipedia.org/wiki/HCCI "HCCI") (Homogeneous Charge Compression Ignition) combustion
- [Scuderi engine](https://en.wikipedia.org/wiki/Scuderi_engine "Scuderi engine")
- [Compound engines](https://en.wikipedia.org/wiki/Compound_engine "Compound engine")
- [Two-stroke diesel engines](https://en.wikipedia.org/wiki/Two-stroke_diesel_engine "Two-stroke diesel engine")
- High-efficiency [gas turbine engines](https://en.wikipedia.org/wiki/Gas_turbine_engine "Gas turbine engine")
- BMW's [Turbosteamer](https://en.wikipedia.org/wiki/Turbosteamer "Turbosteamer") – using the heat from the engine to spin a mini turbine to generate power
- Vehicle electronic control systems that automatically maintain distances between vehicles on motorways/freeways that reduce *ripple back braking*, and consequent re-acceleration.
- Time-optimized piston path, to capture energy from hot gases in the cylinders when they are at their highest temperatures\[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed "Wikipedia:Citation needed")*\]
- sterling hybrid battery vehicle
Many [aftermarket consumer products](https://en.wikipedia.org/wiki/Aftermarket_fuel_economy_device "Aftermarket fuel economy device") exist that are purported to increase fuel economy; many of these claims have been discredited. In the United States, the Environmental Protection Agency maintains a list of devices that have been tested by independent laboratories and makes the test results available to the public.[\[36\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-38)
### Fuel economy maximizing behaviors
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=11 "Edit section: Fuel economy maximizing behaviors")\]
Governments, various environmentalist organizations, and companies like [Toyota](https://en.wikipedia.org/wiki/Toyota "Toyota") and [Shell Oil Company](https://en.wikipedia.org/wiki/Shell_Oil_Company "Shell Oil Company") have historically urged drivers to maintain adequate air pressure in [tires](https://en.wikipedia.org/wiki/Tire "Tire") and careful acceleration/deceleration habits. Keeping track of fuel efficiency stimulates fuel economy-maximizing behavior.[\[37\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-39)
A five-year partnership between [Michelin](https://en.wikipedia.org/wiki/Michelin "Michelin") and [Anglian Water](https://en.wikipedia.org/wiki/Anglian_Water "Anglian Water") shows that 60,000 liters of fuel can be saved on tire pressure. The Anglian Water fleet of 4,000 vans and cars are now lasting their full lifetime. This shows the impact that tire pressures have on the fuel efficiency.[\[38\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-40)
### Fuel economy as part of quality management regimes
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=12 "Edit section: Fuel economy as part of quality management regimes")\]
[Environmental management](https://en.wikipedia.org/wiki/Environmental_management "Environmental management") systems [EMAS](https://en.wikipedia.org/wiki/Eco-Management_and_Audit_Scheme "Eco-Management and Audit Scheme"), as well as good fleet management, includes record-keeping of the fleet fuel consumption. Quality management uses those figures to steer the measures acting on the fleets. This is a way to check whether procurement, driving, and maintenance in total have contributed to changes in the fleet's overall consumption.
## Fuel economy standards and testing procedures
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=13 "Edit section: Fuel economy standards and testing procedures")\]
| Country | 2004 average | Requirement | | | |
|---|---|---|---|---|---|
| 2004 | 2005 | 2008 | Later | | |
| People's Republic of China[\[39\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-41) | | | 6\.9 L/100 km | 6\.9 L/100 km | 6\.1 L/100 km |
| [United States](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#United_States) | 24\.6 mpg (9.5 L/100 km) (cars and trucks)\* | 27 mpg (8.7 L/100 km) (cars only)\* | | | 35 mpg (6.7 L/100 km) (Model Year 2020, cars & light trucks) |
| [European Union](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Europe) | | | | | 4\.1 L/100 km (2020, [NEDC](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Europe)) |
| [Japan](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Japan)[\[11\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-pew-12) | | | | | 6\.7 L/100 km [CAFE](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#CAFE_standards) eq (2010) |
| [Australia](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#Australia)[\[11\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-pew-12) | 8\.08 L/100 km CAFE eq (2002) | none | | | none (as of March 2019)[\[40\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-42) |
\* highway \*\* combined
From October 2008, all new cars had to be sold with a sticker on the windscreen showing the fuel consumption and the CO2 emissions.[\[41\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-43) Fuel consumption figures are expressed as *urban*, *extra urban* and *combined*, measured according to [ECE Regulations](https://en.wikipedia.org/wiki/ECE_Regulations "ECE Regulations") 83 and 101 – which are the based on the [European driving cycle](https://en.wikipedia.org/wiki/New_European_Driving_Cycle "New European Driving Cycle"); previously, only the *combined* number was given.
Australia also uses a star rating system, from one to five stars, that combines greenhouse gases with pollution, rating each from 0 to 10 with ten being best. To get 5 stars a combined score of 16 or better is needed, so a car with a 10 for economy (greenhouse) and a 6 for emission or 6 for economy and 10 for emission, or anything in between would get the highest 5 star rating.[\[42\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-44) The lowest rated car is the [Ssangyong Korrando](https://en.wikipedia.org/wiki/SsangYong_Korando "SsangYong Korando") with automatic transmission, with one star, while the highest rated was the Toyota Prius hybrid. The Fiat 500, Fiat Punto and Fiat Ritmo as well as the Citroen C3 also received 5 stars.[\[43\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-45) The greenhouse rating depends on the fuel economy and the type of fuel used. A greenhouse rating of 10 requires 60 or less grams of CO2 per km, while a rating of zero is more than 440 g/km CO2. The highest greenhouse rating of any 2009 car listed is the Toyota Prius, with 106 g/km CO2 and 4.4 L/100 km (64 mpg‑imp; 53 mpg‑US). Several other cars also received the same rating of 8.5 for greenhouse. The lowest rated was the Ferrari 575 at 499 g/km CO2 and 21.8 L/100 km (13.0 mpg‑imp; 10.8 mpg‑US). The Bentley also received a zero rating, at 465 g/km CO2. The best fuel economy of any year is the 2004–2005 [Honda Insight](https://en.wikipedia.org/wiki/Honda_Insight "Honda Insight"), at 3.4 L/100 km (83 mpg‑imp; 69 mpg‑US).
Vehicle manufacturers follow a controlled laboratory testing procedure to generate the fuel consumption data that they submit to the Government of Canada. This controlled method of fuel consumption testing, including the use of standardized fuels, test cycles and calculations, is used instead of on-road driving to ensure that all vehicles are tested under identical conditions and that the results are consistent and repeatable.
Selected test vehicles are "run in" for about 6,000 km before testing. The vehicle is then mounted on a chassis dynamometer programmed to take into account the aerodynamic efficiency, weight and rolling resistance of the vehicle. A trained driver runs the vehicle through standardized driving cycles that simulate trips in the city and on the highway. Fuel consumption ratings are derived from the emissions generated during the driving cycles.[\[44\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-nrcan.gc.ca-46)
THE 5 CYCLE TEST:
1. The **city test** simulates urban driving in stop-and-go traffic with an average speed of 34 km/h and a top speed of 90 km/h. The test runs for approximately 31 minutes and includes 23 stops. The test begins from a cold engine start, which is similar to starting a vehicle after it has been parked overnight during the summer. The final phase of the test repeats the first eight minutes of the cycle but with a hot engine start. This simulates restarting a vehicle after it has been warmed up, driven and then stopped for a short time. Over five minutes of test time are spent idling, to represent waiting at traffic lights. The ambient temperature of the test cell starts at 20 °C and ends at 30 °C.
2. The **highway test** simulates a mixture of open highway and rural road driving, with an average speed of 78 km/h and a top speed of 97 km/h. The test runs for approximately 13 minutes and does not include any stops. The test begins from a hot engine start. The ambient temperature of the test cell starts at 20 °C and ends at 30 °C.
3. In the **cold temperature operation test**, the same driving cycle is used as in the standard **city test**, except that the ambient temperature of the test cell is set to −7 °C.
4. In the **air conditioning test**, the ambient temperature of the test cell is raised to 35 °C. The vehicle's climate control system is then used to lower the internal cabin temperature. Starting with a warm engine, the test averages 35 km/h and reaches a maximum speed of 88 km/h. Five stops are included, with idling occurring 19% of the time.
5. The **high speed/quick acceleration test** averages 78 km/h and reaches a top speed of 129 km/h. Four stops are included and brisk acceleration maximizes at a rate of 13.6 km/h per second. The engine begins warm and air conditioning is not used. The ambient temperature of the test cell is constantly 25 °C.
Tests 1, 3, 4, and 5 are averaged to create the city driving fuel consumption rate.
Tests 2, 4, and 5 are averaged to create the highway driving fuel consumption rate.[\[44\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-nrcan.gc.ca-46)
[](https://en.wikipedia.org/wiki/File:Irish_Car_CO2_Label.svg)
Irish fuel economy label
In the European Union, passenger vehicles are commonly tested using two drive cycles, and corresponding fuel economies are reported as "urban" and "extra-urban", in liters per 100 km and (in the UK) in miles per imperial gallon.
The urban economy is measured using the test cycle known as ECE-15, first introduced in 1970 by EC Directive 70/220/EWG and finalized by EEC Directive 90/C81/01 in 1999. It simulates a 4,052 m (2.518 mile) urban trip at an average speed of 18.7 km/h (11.6 mph) and at a maximum speed of 50 km/h (31 mph).
The extra-urban driving cycle or EUDC lasts 400 seconds (6 minutes 40 seconds) at an average speed 62.6 km/h (39 mph) and a top speed of 120 km/h (74.6 mph).[\[45\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-47)
EU fuel consumption numbers are often considerably lower than corresponding US EPA test results for the same vehicle. For example, the 2011 [Honda CR-Z](https://en.wikipedia.org/wiki/Honda_CR-Z "Honda CR-Z") with a six-speed manual transmission is rated 6.1/4.4 L/100 km in Europe[\[46\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-48) and 7.6/6.4 L/100 km (31/37 mpg ) in the United States.[\[47\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-49)
In the European Union advertising has to show [carbon dioxide](https://en.wikipedia.org/wiki/Carbon_dioxide "Carbon dioxide") (CO2)-emission and fuel consumption data in a clear way as described in the UK Statutory Instrument 2004 No 1661.[\[48\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-50) Since September 2005 a color-coded "Green Rating" sticker has been available in the UK, which rates fuel economy by CO2 emissions: A: \<= 100 g/km, B: 100–120, C: 121–150, D: 151–165, E: 166–185, F: 186–225, and G: 226+. Depending on the type of fuel used, for gasoline A corresponds to about 4.1 L/100 km (69 mpg‑imp; 57 mpg‑US) and G about 9.5 L/100 km (30 mpg‑imp; 25 mpg‑US).[\[49\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-51) Ireland has a very similar label, but the ranges are slightly different, with A: \<= 120 g/km, B: 121–140, C: 141–155, D: 156–170, E: 171–190, F: 191–225, and G: 226+.[\[50\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-52) From 2020, EU requires manufacturers to average 95 g/km CO2 emission or less, or pay an [excess emissions premium](https://en.wikipedia.org/wiki/Fine_\(penalty\) "Fine (penalty)").[\[51\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-53)
In the UK the ASA (Advertising standards agency) have claimed that fuel consumption figures are misleading. Often the case with European vehicles as the MPG (miles per gallon) figures that can be advertised are often not the same as "real world" driving.
The ASA have said that car manufacturers can use "cheats" to prepare their vehicles for their compulsory fuel efficiency and emissions tests in a way set out to make themselves look as "clean" as possible. This practice is common in gasoline and diesel vehicle tests, but hybrid and electric vehicles are not immune as manufacturers apply these techniques to fuel efficiency.
Car experts\[*[who?](https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style/Words_to_watch#Unsupported_attributions "Wikipedia:Manual of Style/Words to watch")*\] also assert that the *official* MPG figures given by manufacturers do not represent the *true* MPG values from real-world driving.[\[52\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-54) Websites have been set up to show the real-world MPG figures, based on crowd-sourced data from real users, vs the official MPG figures.[\[53\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-55)
The major loopholes in the current EU tests allow car manufacturers a number of "cheats" to improve results. Car manufacturers can:
- Disconnect the alternator, thus no energy is used to recharge the battery;
- Use special lubricants that are not used in production cars, in order to reduce friction;
- Turn off all electrical gadgets i.e. Air Con/Radio;
- Adjust brakes or even disconnect them to reduce friction;
- Tape up cracks between body panels and windows to reduce air resistance;
- Remove Wing mirrors.[\[54\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-56)
According to the results of a 2014 study by the [International Council on Clean Transportation](https://en.wikipedia.org/wiki/International_Council_on_Clean_Transportation "International Council on Clean Transportation") (ICCT), the gap between official and real-world fuel-economy figures in Europe has risen to about 38% in 2013 from 10% in 2001. The analysis found that for private cars, the difference between on-road and official CO2 values rose from around 8% in 2001 to 31% in 2013, and 45% for company cars in 2013. The report is based on data from more than half a million private and company vehicles across Europe. The analysis was prepared by the ICCT together with the [Netherlands Organization for Applied Scientific Research](https://en.wikipedia.org/wiki/Netherlands_Organization_for_Applied_Scientific_Research "Netherlands Organization for Applied Scientific Research") (TNO), and the German Institut für Energie- und Umweltforschung Heidelberg (IFEU).[\[55\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-57)
In 2018 update of the ICCT data the difference between the official and real figures was again 38%.[\[56\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-58)
The evaluation criteria used in Japan reflects driving conditions commonly found, as the typical Japanese driver does not drive as fast as other regions internationally ([Speed limits in Japan](https://en.wikipedia.org/wiki/Speed_limits_in_Japan "Speed limits in Japan")).
The 10–15 mode [driving cycle](https://en.wikipedia.org/wiki/Driving_cycle "Driving cycle") test is the official fuel economy and emission certification test for new light duty vehicles in Japan. Fuel economy is expressed in km/L (kilometers per liter) and emissions are expressed in g/km. The test is carried out on a [dynamometer](https://en.wikipedia.org/wiki/Dynamometer "Dynamometer") and consist of 25 tests which cover idling, acceleration, steady running and deceleration, and simulate typical Japanese urban and/or expressway driving conditions. The running pattern begins with a warm start, lasts for 660 seconds (11 minutes) and runs at speeds up to 70 km/h (43.5 mph).[\[57\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-JapTest01-59)[\[58\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-JapTest02-60) The distance of the cycle is 6.34 km (3.9 mi), average speed of 25.6 km/h (15.9 mph), and duration 892 seconds (14.9 minutes), including the initial 15 mode segment.[\[58\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-JapTest02-60)
A new more demanding test, called the JC08, was established in December 2006 for Japan's new standard that goes into effect in 2015, but it is already being used by several car manufacturers for new cars. The JC08 test is significantly longer and more rigorous than the 10–15 mode test. The running pattern with JC08 stretches out to 1200 seconds (20 minutes), and there are both cold and warm start measurements and top speed is 82 km/h (51.0 mph). The economy ratings of the JC08 are lower than the 10–15 mode cycle, but they are expected to be more real world.[\[57\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-JapTest01-59) The [Toyota Prius](https://en.wikipedia.org/wiki/Toyota_Prius "Toyota Prius") became the first car to meet Japan's new 2015 Fuel Economy Standards measured under the JC08 test.[\[59\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-61)
Starting on 7 April 2008, all cars of up to 3.5 tonnes GVW sold other than private sale need to have a fuel economy sticker applied (if available) that shows the rating from one half star to six stars with the most economic cars having the most stars and the more fuel hungry cars the least, along with the fuel economy in L/100 km and the estimated annual fuel cost for driving 14,000 km (at present fuel prices). The stickers must also appear on vehicles to be leased for more than 4 months. All new cars currently rated range from 6.9 L/100 km (41 mpg‑imp; 34 mpg‑US) to 3.8 L/100 km (74 mpg‑imp; 62 mpg‑US) and received respectively from 4.5 to 5.5 stars.[\[60\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-62)
The [Kingdom of Saudi Arabia](https://en.wikipedia.org/wiki/Kingdom_of_Saudi_Arabia "Kingdom of Saudi Arabia") announced new light-duty vehicle fuel economy standards in November 2014 which became effective 1 January 2016 and will be fully phased in by 1 January 2018 ([Saudi Standards](https://en.wikipedia.org/wiki/Saudi_Standards,_Metrology_and_Quality_Organization "Saudi Standards, Metrology and Quality Organization") regulation SASO-2864). A review of the targets will be carried by December 2018, at which time targets for 2021–2025 will be set.
[](https://en.wikipedia.org/wiki/File:Motor_vehicle_efficiency.png)
Motor vehicle fuel economy from 1949 to 2021
The [Energy Tax Act](https://en.wikipedia.org/wiki/Energy_Tax_Act "Energy Tax Act") of 1978[\[61\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-63) in the US established a gas guzzler tax on the sale of new model year vehicles whose fuel economy fails to meet certain statutory levels. The tax applies only to cars (not trucks) and is collected by the [IRS](https://en.wikipedia.org/wiki/Internal_Revenue_Service "Internal Revenue Service"). Its purpose is to discourage the production and purchase of fuel-inefficient vehicles. The tax was phased in over ten years with rates increasing over time. It applies only to manufacturers and importers of vehicles, although presumably some or all of the tax is passed along to automobile consumers in the form of higher prices. Only new vehicles are subject to the tax, so no tax is imposed on used car sales. The tax is graduated to apply a higher tax rate for less-fuel-efficient vehicles. To determine the tax rate, manufacturers test all the vehicles at their laboratories for fuel economy. The US [Environmental Protection Agency](https://en.wikipedia.org/wiki/United_States_Environmental_Protection_Agency "United States Environmental Protection Agency") confirms a portion of those tests at an EPA lab.
In some cases, this tax may apply only to certain variants of a given model; for example, the 2004–2006 [Pontiac GTO](https://en.wikipedia.org/wiki/Holden_Monaro#Pontiac_GTO "Holden Monaro") (captive import version of the [Holden Monaro](https://en.wikipedia.org/wiki/Holden_Monaro "Holden Monaro")) did incur the tax when ordered with the four-speed automatic transmission, but did not incur the tax when ordered with the six-speed manual transmission.[\[62\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-64)
#### EPA testing procedure through 2007
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=24 "Edit section: EPA testing procedure through 2007")\]
Two separate fuel economy tests simulate city driving and highway driving. The "city" driving cycle is based on the Urban Dynamometer Driving Schedule or (UDDS) or [FTP-72](https://en.wikipedia.org/wiki/FTP-72 "FTP-72"), defined in [40 CFR](https://en.wikipedia.org/wiki/Title_40_of_the_Code_of_Federal_Regulations "Title 40 of the Code of Federal Regulations") [86\.I](https://www.ecfr.gov/current/title-40/section-86.I). The UDDS cycle starts with a cold engine and makes 23 stops over a period of 31 minutes for an average speed of 20 mph (32 km/h) and a top speed of 56 mph (90 km/h). The UDDS procedure has been updated to [FTP-75](https://en.wikipedia.org/wiki/FTP-75 "FTP-75") by adding a "hot start" cycle which repeats the "cold start" cycle after a 10-minute pause.
The "highway" program or Highway Fuel Economy Driving Schedule ([HWFET](https://en.wikipedia.org/wiki/HWFET "HWFET")) is defined in [40 CFR](https://en.wikipedia.org/wiki/Title_40_of_the_Code_of_Federal_Regulations "Title 40 of the Code of Federal Regulations") [600\.I](https://www.ecfr.gov/current/title-40/section-600.I) and uses a warmed-up engine and makes no stops, averaging 48 mph (77 km/h) with a top speed of 60 mph (97 km/h) over a 10-mile (16 km) distance. A weighted average of city (55%) and highway (45%) fuel economies is used to determine the combined rating and guzzler tax.[\[63\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA_cycles-65)[\[64\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-66)[\[65\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-67) This rating is what is also used for light-duty vehicle [corporate average fuel economy](https://en.wikipedia.org/wiki/Corporate_average_fuel_economy "Corporate average fuel economy") regulations.
Because EPA figures had almost always indicated better efficiency than real-world fuel-efficiency, the EPA has modified the method starting with 2008. Updated estimates are available for vehicles back to the 1985 model year.[\[63\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA_cycles-65)[\[66\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-68)
- [](https://en.wikipedia.org/wiki/File:Uddsdds.gif "The \"city\" or Urban Dynamometer Driving Schedule (UDDS) used in the EPA Federal Test Procedure")
The "city" or Urban Dynamometer Driving Schedule (UDDS) used in the EPA Federal Test Procedure
- [](https://en.wikipedia.org/wiki/File:Hwfetdds.gif "The Highway Fuel Economy Driving Cycle (HWFET) used in the EPA Federal Test Procedure")
The Highway Fuel Economy Driving Cycle (HWFET) used in the EPA Federal Test Procedure
#### EPA testing procedure: 2008 and beyond
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=25 "Edit section: EPA testing procedure: 2008 and beyond")\]
[](https://en.wikipedia.org/wiki/File:Fuel_economy_label_EPA_2008.jpg)
2008 [Monroney sticker](https://en.wikipedia.org/wiki/Monroney_sticker "Monroney sticker") highlights fuel economy.
US EPA altered the testing procedure effective MY2008 which adds three new [Supplemental Federal Test Procedure](https://en.wikipedia.org/wiki/United_States_vehicle_emission_standards#Supplemental_Federal_Test_Procedure_\(SFTP\) "United States vehicle emission standards") (SFTP) tests to include the influence of higher driving speed, harder acceleration, colder temperature and air conditioning use.[\[67\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-2008epa_test-69)
SFTP [US06](https://en.wikipedia.org/wiki/US06 "US06") is a high speed/quick acceleration loop that lasts 10 minutes, covers 8 miles (13 km), averages 48 mph (77 km/h) and reaches a top speed of 80 mph (130 km/h). Four stops are included, and brisk acceleration maximizes at a rate of 8.46 mph (13.62 km/h) per second. The engine begins warm and air conditioning is not used. Ambient temperature varies between 68 °F (20 °C) to 86 °F (30 °C).
SFTP [SC03](https://en.wikipedia.org/wiki/SC03 "SC03") is the air conditioning test, which raises ambient temperatures to 95 °F (35 °C), and puts the vehicle's climate control system to use. Lasting 9.9 minutes, the 3.6-mile (5.8 km) loop averages 22 mph (35 km/h) and maximizes at a rate of 54.8 mph (88.2 km/h). Five stops are included, idling occurs 19 percent of the time and acceleration of 5.1 mph per second is achieved. Engine temperatures begin warm.
Lastly, a cold temperature cycle uses the same parameters as the current city loop, except that ambient temperature is set to 20 °F (−7 °C).
EPA tests for fuel economy do not include electrical load tests beyond climate control, which may account for some of the discrepancy between EPA and real world fuel-efficiency. A 200 W electrical load can produce a 0.4 km/L (0.94 mpg) reduction in efficiency on the FTP 75 cycle test.[\[33\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ieee-35)
Beginning with model year 2017 the calculation method changed to improve the accuracy of the estimated 5-cycle city and highway fuel economy values derived from just the FTP and HFET tests, with lower uncertainty for fuel efficient vehicles.[\[68\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-70)
#### Electric vehicles and hybrids
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=26 "Edit section: Electric vehicles and hybrids")\]
[](https://en.wikipedia.org/wiki/File:Chevy_Volt_EPA_Fuel_Economy_Official_Label.png)
2010 [Monroney sticker](https://en.wikipedia.org/wiki/Monroney_sticker "Monroney sticker") for a [plug-in hybrid](https://en.wikipedia.org/wiki/Plug-in_hybrid "Plug-in hybrid") showing fuel economy in [all-electric mode](https://en.wikipedia.org/wiki/All-electric_mode "All-electric mode") and gasoline-only mode
Following the efficiency claims made for vehicles such as [Chevrolet Volt](https://en.wikipedia.org/wiki/Chevrolet_Volt "Chevrolet Volt") and [Nissan Leaf](https://en.wikipedia.org/wiki/Nissan_Leaf "Nissan Leaf"), the [National Renewable Energy Laboratory](https://en.wikipedia.org/wiki/National_Renewable_Energy_Laboratory "National Renewable Energy Laboratory") recommended to use EPA's new vehicle fuel efficiency formula that gives different values depending on fuel used.[\[69\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-71) In November 2010 the EPA introduced the first fuel economy ratings in the [Monroney stickers](https://en.wikipedia.org/wiki/Monroney_sticker "Monroney sticker") for [plug-in electric vehicles](https://en.wikipedia.org/wiki/Plug-in_electric_vehicle "Plug-in electric vehicle").
For the fuel economy label of the Chevy Volt [plug-in hybrid](https://en.wikipedia.org/wiki/Plug-in_hybrid "Plug-in hybrid") EPA rated the car separately for [all-electric mode](https://en.wikipedia.org/wiki/All-electric_mode "All-electric mode") expressed in [miles per gallon gasoline equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent "Miles per gallon gasoline equivalent") (MPG-e) and for gasoline-only mode expressed in conventional miles per gallon. EPA also estimated an overall combined city/highway gas-electricity fuel economy rating expressed in miles per gallon gasoline equivalent (MPG-e). The label also includes a table showing fuel economy and electricity consumed for five different scenarios: 30 miles (48 km), 45 miles (72 km), 60 miles (97 km) and 75 miles (121 km) driven between a full charge, and a never charge scenario. This information was included to make the consumers aware of the variability of the fuel economy outcome depending on miles driven between charges. Also the fuel economy for a gasoline-only scenario (never charge) was included. For electric-only mode the energy consumption estimated in [kWh](https://en.wikipedia.org/wiki/KWh "KWh") per 100 miles (160 km) is also shown.[\[70\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-GCCEPAVolt-72)[\[71\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPAmpge-73)
[](https://en.wikipedia.org/wiki/File:Nissan_Leaf_EPA_fuel_economy_label.jpg)
2010 [Monroney label](https://en.wikipedia.org/wiki/Monroney_label "Monroney label") showing the EPA's combined city/highway [fuel economy equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent "Miles per gallon gasoline equivalent") for an all-[electric car](https://en.wikipedia.org/wiki/Electric_car "Electric car"), in this case a 2010 [Nissan Leaf](https://en.wikipedia.org/wiki/Nissan_Leaf "Nissan Leaf")
For the fuel economy label of the Nissan Leaf [electric car](https://en.wikipedia.org/wiki/Electric_car "Electric car") EPA rated the combined fuel economy in terms of [miles per gallon gasoline equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent "Miles per gallon gasoline equivalent"), with a separate rating for city and highway driving. This fuel economy equivalence is based on the energy consumption estimated in [kWh](https://en.wikipedia.org/wiki/KWh "KWh") per 100 miles, and also shown in the Monroney label.[\[72\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-NYTEPA-74)
In May 2011, the [National Highway Traffic Safety Administration](https://en.wikipedia.org/wiki/National_Highway_Traffic_Safety_Administration "National Highway Traffic Safety Administration") (NHTSA) and EPA issued a joint final rule establishing new requirements for a [fuel economy and environment label](https://en.wikipedia.org/wiki/Fuel_economy_and_environment_label "Fuel economy and environment label") that is mandatory for all new passenger cars and trucks starting with [model year](https://en.wikipedia.org/wiki/Model_year "Model year") 2013, and voluntary for 2012 models. The ruling includes new labels for [alternative fuel](https://en.wikipedia.org/wiki/Alternative_fuel "Alternative fuel") and [alternative propulsion](https://en.wikipedia.org/wiki/Alternative_propulsion "Alternative propulsion") vehicles available in the US market, such as [plug-in hybrids](https://en.wikipedia.org/wiki/Plug-in_hybrid "Plug-in hybrid"), [electric vehicles](https://en.wikipedia.org/wiki/Electric_vehicle "Electric vehicle"), [flexible-fuel vehicles](https://en.wikipedia.org/wiki/Flexible-fuel_vehicle "Flexible-fuel vehicle"), [hydrogen fuel cell vehicle](https://en.wikipedia.org/wiki/Fuel_cell_vehicle "Fuel cell vehicle"), and [natural gas vehicles](https://en.wikipedia.org/wiki/Natural_gas_vehicle "Natural gas vehicle").[\[73\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA2013-75)[\[74\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-GCC2013-76) The common fuel economy metric adopted to allow the comparison of alternative fuel and advanced technology vehicles with conventional [internal combustion engine](https://en.wikipedia.org/wiki/Internal_combustion_engine "Internal combustion engine") vehicles is [miles per gallon of gasoline equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_of_gasoline_equivalent "Miles per gallon of gasoline equivalent") (MPGe). A gallon of gasoline equivalent means the number of kilowatt-hours of electricity, cubic feet of [compressed natural gas](https://en.wikipedia.org/wiki/Compressed_natural_gas "Compressed natural gas") (CNG), or kilograms of [hydrogen](https://en.wikipedia.org/wiki/Hydrogen "Hydrogen") that is equal to the energy in a gallon of gasoline.[\[73\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA2013-75)
The new labels also include for the first time an estimate of how much fuel or electricity it takes to drive 100 miles (160 km), providing US consumers with fuel consumption per distance traveled, the metric commonly used in many other countries. EPA explained that the objective is to avoid the traditional miles per gallon metric that can be potentially misleading when consumers compare fuel economy improvements, and known as the "MPG illusion"[\[75\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-77) – this illusion arises because the reciprocal (i.e. non-linear) relationship between cost (equivalently, volume of fuel consumed) per unit distance driven and MPG value means that *differences* in MPG values are not directly meaningful – only ratios are (in mathematical terms, the reciprocal function does not commute with addition and subtraction; in general, a difference in reciprocal values is not equal to the reciprocal of their difference). It has been claimed that many consumers are unaware of this, and therefore compare MPG values by subtracting them, which can give a misleading picture of relative differences in fuel economy between different pairs of vehicles – for instance, an increase from 10 to 20 MPG corresponds to a 100% improvement in fuel economy, whereas an increase from 50 to 60 MPG is only a 20% improvement, although in both cases the difference is 10 MPG.[\[76\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-78) The EPA explained that the new gallons-per-100-miles metric provides a more accurate measure of fuel efficiency[\[73\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA2013-75)[\[77\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-79) – notably, it is equivalent to the normal metric measurement of fuel economy, liters per 100 kilometers (L/100 km).
[](https://en.wikipedia.org/wiki/File:CAFE_mpg_curve_from_NHTSA%27s_Summary_of_Fuel_Economy_Performance,_December_2014.svg)
Curve of average car mileage for model years between 1978 and 2014
The Corporate Average Fuel Economy (CAFE) regulations in the United States, first enacted by Congress in 1975,[\[78\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-80) are federal regulations intended to improve the average fuel economy of cars and light trucks (trucks, vans and [sport utility vehicles](https://en.wikipedia.org/wiki/Sport_utility_vehicle "Sport utility vehicle")) sold in the US in the wake of the [1973 Arab Oil Embargo](https://en.wikipedia.org/wiki/1973_oil_crisis "1973 oil crisis"). Historically, it is the sales-weighted average fuel economy of a manufacturer's [fleet](https://en.wikipedia.org/wiki/Fleet_vehicle "Fleet vehicle") of current [model year](https://en.wikipedia.org/wiki/Model_year "Model year") passenger cars or light trucks, manufactured for sale in the United States. Under Truck CAFE standards 2008–2011 this changes to a "footprint" model where larger trucks are allowed to consume more fuel. The standards were limited to vehicles under a certain weight, but those weight classes were expanded in 2011.
#### Federal and state regulations
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=28 "Edit section: Federal and state regulations")\]
The [Clean Air Act](https://en.wikipedia.org/wiki/Clean_Air_Act_\(United_States\) "Clean Air Act (United States)") of 1970 prohibited states from establishing their own air pollution standards. However, the legislation authorized the EPA to grant a waiver to California, allowing the state to set higher standards.[\[79\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-NYTApril18-81) The law provides a “piggybacking” provision that allows other states to adopt vehicle emission limits that are the same as California's.[\[80\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-ELQSept03-82) California's waivers were routinely granted until 2007, when the [George W. Bush administration](https://en.wikipedia.org/wiki/Presidency_of_George_W._Bush "Presidency of George W. Bush") rejected the state's bid to adopt global warming pollution limits for cars and light trucks.[\[81\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-NYTDec07-83) California and 15 other states that were trying to put in place the same emissions standards sued in response.[\[82\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-WaPoJan08-84) The case was tied up in court until the [Obama administration](https://en.wikipedia.org/wiki/Presidency_of_Barack_Obama "Presidency of Barack Obama") reversed the policy in 2009 by granting the waiver.[\[83\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-GTMJune09-85)
In August 2012, President Obama announced new standards for American-made automobiles of an average of 54.5 miles per gallon by the year 2025.[\[84\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-86)[\[85\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-87) In April 2018, EPA Administrator [Scott Pruitt](https://en.wikipedia.org/wiki/Scott_Pruitt "Scott Pruitt") announced that the [Trump administration](https://en.wikipedia.org/wiki/First_presidency_of_Donald_Trump "First presidency of Donald Trump") planned to roll back the 2012 federal standards and would also seek to curb California's authority to set its own standards.[\[79\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-NYTApril18-81) Although the Trump administration was reportedly considering a compromise to allow state and national standards to stay in place,[\[86\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-NYT2018-88) on 21 February 2019 the White House declared that it had abandoned these negotiations.[\[87\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-89) A government report subsequently found that, in 2019, new light-duty vehicle fuel economy fell 0.2 miles per gallon (to 24.9 miles per gallon) and pollution increased 3 grams per mile traveled (to 356 grams per mile). A decrease in fuel economy and an increase in pollution had not occurred for the previous five years.[\[88\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-90) The Obama-era rule was officially rolled back on 31 March 2020 during the Trump administration,[\[89\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-91) but the rollback was reversed on 20 December 2021 during the Biden administration.[\[90\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-92)
## Fuel economy of trucks
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=29 "Edit section: Fuel economy of trucks")\]
Trucks are usually bought as an investment good. They are meant to earn money. As the Diesel fuel burnt in heavy trucks accounts for around 30%[\[91\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-:0-93) of the total costs for a freight forwarding company there is always a lot of interest in both the haulage industry and the truck builder industry to strive for best fuel economy. For truck buyers the fuel economy measured by standard procedures is only a first guideline. Professional trucking companies measure the fuel economy of their trucks and truck fleets in real usage. Fuel economy of trucks in real usage is determined by four important factors:[\[91\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-:0-93) The truck technology that is constantly improved by the various OEMs. The driver's driving style contributes a lot to the real fuel economy (different from the test cycles where a standard driving style is used). The maintenance condition of the vehicle influences the fuel efficiency – again different from standardized procedures where the trucks are always presented in flawless condition. Last but not least the usage of the vehicle influences the fuel consumption: Hilly roads and heavy loads will increase the fuel consumption of a vehicle.
## Effect on pollution
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=30 "Edit section: Effect on pollution")\]
Fuel efficiency directly affects emissions causing pollution by affecting the amount of fuel used. However, it also depends on the fuel source used to drive the vehicle concerned. Cars for example, can run on a number of fuel types other than gasoline, such as [natural gas](https://en.wikipedia.org/wiki/Natural_gas_vehicle "Natural gas vehicle"), [LPG](https://en.wikipedia.org/wiki/Liquefied_petroleum_gas "Liquefied petroleum gas") or [biofuel](https://en.wikipedia.org/wiki/Biofuel "Biofuel") or electricity which creates various quantities of atmospheric pollution.
A kilogram of carbon, whether contained in petrol, diesel, kerosene, or any other hydrocarbon fuel in a vehicle, leads to approximately 3.6 kg of [CO2](https://en.wikipedia.org/wiki/CO2 "CO2") emissions.[\[92\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA_CO2_est-94) Due to the carbon content of gasoline, its combustion emits 2.3 kg/L (19.4 lb/US gal) of [CO2](https://en.wikipedia.org/wiki/CO2 "CO2"); since diesel fuel is more energy dense per unit volume, diesel emits 2.6 kg/L (22.2 lb/US gal).[\[92\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-EPA_CO2_est-94) This figure is only the CO2 emissions of the final fuel product and does not include additional CO2 emissions created during the drilling, pumping, transportation and refining steps required to produce the fuel. Additional measures to reduce overall emission includes improvements to the efficiency of [air conditioners](https://en.wikipedia.org/wiki/Air_conditioner "Air conditioner"), lights and tires.
US Gallons
- 1 mpg ≈ 0.425 km/L
- 235\.2/mpg ≈ L/100 km
- 1 mpg ≈ 1.201 mpg (imp)
Imperial gallons
- 1 mpg ≈ 0.354 km/L
- 282/mpg ≈ L/100 km
- 1 mpg ≈ 0.833 mpg (US)
### Conversion from mpg
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=32 "Edit section: Conversion from mpg")\]
| | | | |
|---|---|---|---|
| mpg (imp) | mpg (US) | km/L | L/100 km |
| 5 | 4\.2 | 1\.8 | 56\.5 |
| 10 | 8\.3 | 3\.5 | 28\.2 |
| 15 | 12\.5 | 5\.3 | 18\.8 |
| 20 | 16\.7 | 7\.1 | 14\.1 |
| 25 | 20\.8 | 8\.9 | 11\.3 |
| 30 | 25\.0 | 10\.6 | 9\.4 |
| 35 | 29\.1 | 12\.4 | 8\.1 |
| 40 | 33\.3 | 14\.2 | 7\.1 |
| 45 | 37\.5 | 15\.9 | 6\.3 |
| 50 | 41\.6 | 17\.7 | 5\.6 |
| 55 | 45\.8 | 19\.5 | 5\.1 |
| 60 | 50\.0 | 21\.2 | 4\.7 |
| 65 | 54\.1 | 23\.0 | 4\.3 |
| 70 | 58\.3 | 24\.8 | 4\.0 |
| 75 | 62\.5 | 26\.6 | 3\.8 |
| 80 | 66\.6 | 28\.3 | 3\.5 |
| 85 | 70\.8 | 30\.1 | 3\.3 |
| 90 | 74\.9 | 31\.9 | 3\.1 |
| 95 | 79\.1 | 33\.6 | 3\.0 |
| 100 | 83\.3 | 35\.4 | 2\.8 |
| mpg (US) | mpg (imp) | km/L | L/100 km |
| 5 | 6\.0 | 2\.1 | 47\.0 |
| 10 | 12\.0 | 4\.3 | 23\.5 |
| 15 | 18\.0 | 6\.4 | 15\.7 |
| 20 | 24\.0 | 8\.5 | 11\.8 |
| 25 | 30\.0 | 10\.6 | 9\.4 |
| 30 | 36\.0 | 12\.8 | 7\.8 |
| 35 | 42\.0 | 14\.9 | 6\.7 |
| 40 | 48\.0 | 17\.0 | 5\.9 |
| 45 | 54\.0 | 19\.1 | 5\.2 |
| 50 | 60\.0 | 21\.3 | 4\.7 |
| 55 | 66\.1 | 23\.4 | 4\.3 |
| 60 | 72\.1 | 25\.5 | 3\.9 |
| 65 | 78\.1 | 27\.6 | 3\.6 |
| 70 | 84\.1 | 29\.8 | 3\.4 |
| 75 | 90\.1 | 31\.9 | 3\.1 |
| 80 | 96\.1 | 34\.0 | 2\.9 |
| 85 | 102\.1 | 36\.1 | 2\.8 |
| 90 | 108\.1 | 38\.3 | 2\.6 |
| 95 | 114\.1 | 40\.4 | 2\.5 |
| 100 | 120\.1 | 42\.5 | 2\.4 |
### Conversion from km/L and L/100 km
\[[edit](https://en.wikipedia.org/w/index.php?title=Fuel_economy_in_automobiles&action=edit§ion=33 "Edit section: Conversion from km/L and L/100 km")\]
| | | | |
|---|---|---|---|
| L/100 km | km/L | mpg (US) | mpg (imp) |
| 1 | 100\.0 | 235\.2 | 282\.5 |
| 2 | 50\.0 | 117\.6 | 141\.2 |
| 3 | 33\.3 | 78\.4 | 94\.2 |
| 4 | 25\.0 | 58\.8 | 70\.6 |
| 5 | 20\.0 | 47\.0 | 56\.5 |
| 6 | 16\.7 | 39\.2 | 47\.1 |
| 7 | 14\.3 | 33\.6 | 40\.4 |
| 8 | 12\.5 | 29\.4 | 35\.3 |
| 9 | 11\.1 | 26\.1 | 31\.4 |
| 10 | 10\.0 | 23\.5 | 28\.2 |
| 15 | 6\.7 | 15\.7 | 18\.8 |
| 20 | 5\.0 | 11\.8 | 14\.1 |
| 25 | 4\.0 | 9\.4 | 11\.3 |
| 30 | 3\.3 | 7\.8 | 9\.4 |
| 35 | 2\.9 | 6\.7 | 8\.1 |
| 40 | 2\.5 | 5\.9 | 7\.1 |
| 45 | 2\.2 | 5\.2 | 6\.3 |
| 50 | 2\.0 | 4\.7 | 5\.6 |
| 55 | 1\.8 | 4\.3 | 5\.1 |
| 60 | 1\.7 | 3\.9 | 4\.7 |
| km/L | L/100 km | mpg (US) | mpg (imp) |
| 5 | 20\.0 | 11\.8 | 14\.1 |
| 10 | 10\.0 | 23\.5 | 28\.2 |
| 15 | 6\.7 | 35\.3 | 42\.4 |
| 20 | 5\.0 | 47\.0 | 56\.5 |
| 25 | 4\.0 | 58\.8 | 70\.6 |
| 30 | 3\.3 | 70\.6 | 84\.7 |
| 35 | 2\.9 | 82\.3 | 98\.9 |
| 40 | 2\.5 | 94\.1 | 113\.0 |
| 45 | 2\.2 | 105\.8 | 127\.1 |
| 50 | 2\.0 | 117\.6 | 141\.2 |
| 55 | 1\.8 | 129\.4 | 155\.4 |
| 60 | 1\.7 | 141\.1 | 169\.5 |
| 65 | 1\.5 | 152\.9 | 183\.6 |
| 70 | 1\.4 | 164\.7 | 197\.7 |
| 75 | 1\.3 | 176\.4 | 211\.9 |
| 80 | 1\.3 | 188\.2 | 226\.0 |
| 85 | 1\.2 | 199\.9 | 240\.1 |
| 90 | 1\.1 | 211\.7 | 254\.2 |
| 95 | 1\.1 | 223\.5 | 268\.4 |
| 100 | 1\.0 | 235\.2 | 282\.5 |
- [Automobile costs](https://en.wikipedia.org/wiki/Automobile_costs "Automobile costs")
- [ACEA agreement](https://en.wikipedia.org/wiki/ACEA_agreement "ACEA agreement")
- [Battery electric vehicle](https://en.wikipedia.org/wiki/Battery_electric_vehicle "Battery electric vehicle")
- [Car speed and energy consumption](https://en.wikipedia.org/wiki/Car_speed_and_energy_consumption "Car speed and energy consumption")
- [Car tuning](https://en.wikipedia.org/wiki/Car_tuning "Car tuning")
- [Climate crisis](https://en.wikipedia.org/wiki/Climate_crisis "Climate crisis")
- [Emission standard](https://en.wikipedia.org/wiki/Emission_standard "Emission standard")
- [Energy conservation](https://en.wikipedia.org/wiki/Energy_conservation "Energy conservation")
- [Energy-efficient driving](https://en.wikipedia.org/wiki/Energy-efficient_driving "Energy-efficient driving")
- [FF layout](https://en.wikipedia.org/wiki/FF_layout "FF layout")
- [Fuel efficiency in transportation](https://en.wikipedia.org/wiki/Fuel_efficiency_in_transportation "Fuel efficiency in transportation")
- [Fuel saving devices](https://en.wikipedia.org/wiki/Fuel_saving_devices "Fuel saving devices")
- [Gasoline gallon equivalent](https://en.wikipedia.org/wiki/Gasoline_gallon_equivalent "Gasoline gallon equivalent")
- [Motorized quadricycle](https://en.wikipedia.org/wiki/Motorized_quadricycle "Motorized quadricycle") (vehicles with low power engines/low top speed)
- [Miles per gallon gasoline equivalent](https://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent "Miles per gallon gasoline equivalent")
- [Passenger miles per gallon](https://en.wikipedia.org/wiki/Passenger_miles_per_gallon "Passenger miles per gallon")
- [The Very Light Car](https://en.wikipedia.org/wiki/The_Very_Light_Car "The Very Light Car")
- [Vehicle Efficiency Initiative](https://en.wikipedia.org/wiki/Vehicle_Efficiency_Initiative "Vehicle Efficiency Initiative")
- [Vehicle metrics](https://en.wikipedia.org/wiki/Vehicle_metrics "Vehicle metrics")
- [Green vehicle](https://en.wikipedia.org/wiki/Green_vehicle "Green vehicle")
- [Low-carbon economy](https://en.wikipedia.org/wiki/Low-carbon_economy "Low-carbon economy")
- [Low-rolling resistance tires](https://en.wikipedia.org/wiki/Low-rolling_resistance_tires "Low-rolling resistance tires")
- [Microcar](https://en.wikipedia.org/wiki/Microcar "Microcar")
- [Plug-in hybrid](https://en.wikipedia.org/wiki/Plug-in_hybrid "Plug-in hybrid")
1. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-7)** Specifically, the production-weighted [harmonic mean](https://en.wikipedia.org/wiki/Harmonic_mean "Harmonic mean")
2. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-16)** The 2.2% drop figure was calculated by finding daily consumption to be 9,299,684 barrels of petroleum. Obtain 1973's petroleum consumption from transportation sector at 2.1e from the Energy Consumption by Sector section, then convert to barrels using A1 in the Thermal Conversion Factors section (assume "conventional motor gasoline" since ethanol-based or purportedly smog-reducing gas was not common in 1973).[\[14\]](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_note-15)
1. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-1)**
Page, Walter Hines; Page, Arthur Wilson (1916). ["Man and His Machines"](https://books.google.com/books?id=lPAMVa7esS4C). *The World's Work*. Vol. XXXIII. Garden City, New York: Doubleday, Page & Co.
2. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-2)**
["What counts as 'good' MPG nowadays?"](https://www.thejournal.ie/dear-driver-what-is-good-mpg-3150884-Dec2016/). 21 December 2016.
3. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-3)** [The New Fuel Economy Label](https://www.fueleconomy.gov/feg/label/learn-more-gasoline-label.shtml) at FuelEconomy.gov
4. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA_AutomotiveTrends_202212_4-0)**
["Highlights of the Automotive Trends Report"](https://www.epa.gov/automotive-trends/highlights-automotive-trends-report). *EPA.gov*. U.S. Environmental Protection Agency (EPA). 12 December 2022. [Archived](https://web.archive.org/web/20230902145941/https://www.epa.gov/automotive-trends/highlights-automotive-trends-report) from the original on 2 September 2023.
5. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-GlobalFuelEfficInit_202311_5-0)**
Cazzola, Pierpaolo; Paoli, Leonardo; Teter, Jacob (November 2023). ["Trends in the Global Vehicle Fleet 2023 / Managing the SUV Shift and the EV Transition"](https://www.globalfueleconomy.org/media/792523/gfei-trends-in-the-global-vehicle-fleet-2023-spreads.pdf) (PDF). Global Fuel Economy Initiative (GFEI). p. 3. [doi](https://en.wikipedia.org/wiki/Doi_\(identifier\) "Doi (identifier)"):[10\.7922/G2HM56SV](https://doi.org/10.7922%2FG2HM56SV). [Archived](https://web.archive.org/web/20231126092826/https://www.globalfueleconomy.org/media/792523/gfei-trends-in-the-global-vehicle-fleet-2023-spreads.pdf) (PDF) from the original on 26 November 2023.
6. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-6)**
Paul R. Portney; Ian W.H. Parry; Howard K. Gruenspecht; Winston Harrington (November 2003). ["The Economics of Fuel Economy Standards"](https://web.archive.org/web/20071201031917/http://www.rff.org/documents/RFF-DP-03-44.pdf) (PDF). Resources for the Future. Archived from [the original](http://www.rff.org/documents/RFF-DP-03-44.pdf) (PDF) on 1 December 2007. Retrieved 4 January 2008.
7. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-8)**
["Highlights of the Automotive Trends Report"](https://www.epa.gov/automotive-trends/highlights-automotive-trends-report). *US EPA*. November 2021. Retrieved 30 November 2021.
8. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-2019_epa_BestandWorst_9-0)**
["2019 Best and Worst Fuel Economy Vehicles"](https://www.fueleconomy.gov/feg/best-worst.shtml). US EPA. Retrieved 23 June 2019.
9. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-10)** [Reducing CO2 emissions from passenger cars – Policies – Climate Action – European Commission](http://ec.europa.eu/clima/policies/transport/vehicles/cars_en.htm). Ec.europa.eu (9 December 2010). Retrieved 21 September 2011.
10. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-11)** [Myth: Cars are becoming more fuel efficient](http://www.ptua.org.au/myths/efficient.shtml). Ptua.org.au. Retrieved 21 September 2011.
11. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-pew_12-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-pew_12-1) [***c***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-pew_12-2) [Comparison of Passenger Vehicle Fuel Economy and GHG Emission Standards Around the World at Pew Center on Global Climate Change](http://www.pewclimate.org/docUploads/Fuel%20Economy%20and%20GHG%20Standards_010605_110719.pdf) [Archived](https://web.archive.org/web/20080413221041/http://www.pewclimate.org/docUploads/Fuel%20Economy%20and%20GHG%20Standards_010605_110719.pdf) 13 April 2008 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). (PDF). Retrieved 21 September 2011.
12. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ornl_13-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ornl_13-1) [***c***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ornl_13-2) [Steady Speed Fuel Economy](http://cta.ornl.gov/data/tedb31/Edition31_Full_Doc.pdf) [Archived](https://web.archive.org/web/20120924201205/http://cta.ornl.gov/data/tedb31/Edition31_Full_Doc.pdf) 24 September 2012 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine") "The two earlier studies by the Federal Highway Administration (FHWA) indicate maximum fuel efficiency was achieved at speeds of 35 to 40 mph (55 to 65 km/h). The recent FHWA study indicates greater fuel efficiency at higher speeds."
13. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-14)**
Cowan, Edward (27 November 1973). "Politics and Energy: Nixon's Silence on Rationing Reflects Hope That Austerity Can Be Avoided". *The New York Times*. p. 30.
14. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-15)**
Staff (28 June 2008). [*Annual Energy Review*](https://web.archive.org/web/20180926014110/https://www.eia.gov/FTPROOT/multifuel/038407.pdf) (PDF) (2007 ed.). Washington, DC: Energy Information Administration. Archived from [the original](https://www.eia.gov/FTPROOT/multifuel/038407.pdf) (PDF) on 26 September 2018.
15. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-17)**
["55 Mile-per-hour Speed Limit Approved by House"](http://infoweb.newsbank.com/iw-search/we/HistArchive/?p_action=doc&p_queryname=3&p_docid=0FCAA40565438742&p_docnum=20&s_pagesearch=no&s_ARTICLE_ID=0FCAA40565438742&s_RELEASE=release_0005&s_ISSUE_ID=0FCAA4036C446D57&s_FORMAT=gif&s_SIZE=display&s_SEARCHED=%28+%28%28pty%253A10+%29+OR+%28pty%253A40+%29+OR+%28pty%253A50+%29+OR+%28pty%253A60+%29%29+%29+and+%28+ibd%253A%255B2441684%253B2442414%255D+%29+and+%28+%2855%29+AND+%28speed++AND+limit%29+%29+&p_product=DMHA&p_theme=dmn&p_nbid=R5FY50FIMTIxNjc0NDY1Mi4yNjE1OjE6MTU6MTI5LjExOS4yNDguMjUx). [United Press International](https://en.wikipedia.org/wiki/United_Press_International "United Press International"). 4 December 1973. p. 30. Retrieved 22 July 2008.
(subscription required)
16. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-18)**
["Special Report 254: Managing Speed"](https://onlinepubs.trb.org/onlinepubs/sr/sr254.pdf) (PDF). [Transportation Research Board](https://en.wikipedia.org/wiki/Transportation_Research_Board "Transportation Research Board"): 189. Retrieved 17 September 2014. "Bloomquist (1984) estimated that the 1974 National Maximum Speed Limit (NMSL) reduced fuel consumption by 0.2 to 1.0 percent."
17. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-19)**
["Highway Statistics 1973 (Table VM-2: VEHICLE MILES, BY STATE AND HIGHWAY SYSTEM-1973)"](https://web.archive.org/web/20130304135803/http://isddc.dot.gov/OLPFiles/FHWA/012894.pdf) (PDF). [Federal Highway Administration](https://en.wikipedia.org/wiki/Federal_Highway_Administration "Federal Highway Administration"): 76. Archived from [the original](http://isddc.dot.gov/OLPFiles/FHWA/012894.pdf) (PDF) on 4 March 2013. Retrieved 17 September 2014.
18. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-greenvehicleguide.gov.au_20-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-greenvehicleguide.gov.au_20-1)
["Lexus IS250 2.5L 6cyl, Auto 6 speed Sedan, 5 seats, 2WD"](http://www.greenvehicleguide.gov.au/GVGPublicUI/CompareVehicles.aspx).
`{{cite web}}`: CS1 maint: deprecated archival service ([link](https://en.wikipedia.org/wiki/Category:CS1_maint:_deprecated_archival_service "Category:CS1 maint: deprecated archival service"))
19. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-lexus.de_21-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-lexus.de_21-1)
*IS 250 Kraftstoffverbrauch kombiniert 8,9 L/100 km (innerorts 12,5 L/ außerorts 6,9 L) bei CO2-Emissionen von 209 g/km nach dem vorgeschriebenen EU-Messverfahren*
["LEXUS – Lexus – IS – Sportlimousine – Cabriolet – Cabrio – Kabrio – Coupé – Coupe – Hochleistung IS F – High-Performance-Fahrzeug IS F"](https://web.archive.org/web/20100402102635/http://www.lexus.de/range/IS/Index.aspx). Archived from [the original](http://www.lexus.de/range/is/index.aspx) on 2 April 2010. Retrieved 22 April 2010.
20. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-fueleconomy.gov_22-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-fueleconomy.gov_22-1) *2009 Lexus IS 250 6 cyl, 2.5 L, Automatic (S6), Premium* [http://www.fueleconomy.gov/feg/findacar.htm](https://www.fueleconomy.gov/feg/findacar.htm)
21. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-23)**
["Gas prices too high? Try Europe"](https://www.csmonitor.com/2005/0826/p01s03-woeu.html). *Christian Science Monitor*. 26 August 2005. [Archived](https://web.archive.org/web/20120918025725/http://www.csmonitor.com/2005/0826/p01s03-woeu.html) from the original on 18 September 2012.
22. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-24)**
["U.S. 'stuck in reverse' on fuel economy"](https://web.archive.org/web/20141206112123/http://www.nbcnews.com/id/17344368/). *[NBC News](https://en.wikipedia.org/wiki/NBC_News "NBC News")*. 28 February 2007. Archived from [the original](http://www.nbcnews.com/id/17344368) on 6 December 2014.
23. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-25)**
["VW Lupo: Rough road to fuel economy"](http://usatoday30.usatoday.com/money/consumer/autos/mareview/mauto497.htm).
24. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-26)** [Heavy Vehicles and Characteristics](http://cta.ornl.gov/data/chapter5.shtml) [Archived](https://web.archive.org/web/20120723162849/http://cta.ornl.gov/data/chapter5.shtml) 2012-07-23 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine") Table 5.4
25. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-27)** [Light Vehicles and Characteristics](http://cta.ornl.gov/data/chapter4.shtml) [Archived](https://web.archive.org/web/20120915163525/http://cta.ornl.gov/data/chapter4.shtml) 2012-09-15 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine") Table 4.1
26. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-28)** [How Do Gasoline Prices Affect Fleet Fuel Economy?](http://www.aeaweb.org/articles.php?doi=10.1257/pol.1.2.113) [Archived](https://web.archive.org/web/20121021131856/http://www.aeaweb.org/articles.php?doi=10.1257%2Fpol.1.2.113) 2012-10-21 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine")
27. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-twsMercuryNews_29-0)** Dee-Ann Durbin of the Associated Press, June 17, 2014, Mercury News, [Auto industry gets serious about lighter materials](http://www.mercurynews.com/business/ci_25981045/auto-industry-gets-serious-about-lighter-materials) [Archived](https://web.archive.org/web/20150415082011/http://www.mercurynews.com/business/ci_25981045/auto-industry-gets-serious-about-lighter-materials) 2015-04-15 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"), Retrieved April 11, 2015, "...Automakers have been experimenting for decades with lightweighting... the effort is gaining urgency with the adoption of tougher gas mileage standards. ..."
28. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-30)**
Yang, Zifei; Bandivadekar, Anup. ["Light-duty vehicle greenhouse gas and fuel economy standards"](http://www.theicct.org/sites/default/files/publications/2017-Global-LDV-Standards-Update_ICCT-Report_23062017_vF.pdf) (PDF). International Council on Clean Transportation. Retrieved 1 December 2017.
29. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-31)**
["Lexus IS – Driving in every sense"](https://www.lexus.ca/lexus/en/automobiles/is#intro_text). *Lexus Canada*.
30. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-32)**
["TRANSPORTATION RESEARCH BOARD SPECIAL REPORT 286 TIRES AND PASSENGER VEHICLE FUEL ECONOMY, Transportation Research Board, National Academy of Sciences p.62-65 of pdf, p.39-42 of the report. Retrieved 22 October 2014"](https://onlinepubs.trb.org/onlinepubs/sr/sr286.pdf) (PDF).
31. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-33)** [Wheels, online road load, and MPG calculator](http://www.virtual-car.org/wheels/wheels-road-load-calculation.html). Virtual-car.org (3 August 2009). Retrieved 21 September 2011.
32. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-34)** [An Overview of Current Automatic, Manual and Continuously Variable Transmission Efficiencies and Their Projected Future Improvements](http://www.sae.org/servlets/productDetail?PROD_TYP=PAPER&PROD_CD=1999-01-1259). SAE.org (1 March 1999). Retrieved 21 September 2011.
33. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ieee_35-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ieee_35-1) [Automotive Electrical Systems Circa 2005](http://www.spectrum.ieee.org/print/1420) [Archived](https://web.archive.org/web/20090203012939/http://www.spectrum.ieee.org/print/1420) 3 February 2009 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). Spectrum.ieee.org. Retrieved 21 September 2011.
34. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-36)** [Low-rolling resistance tires](https://en.wikipedia.org/wiki/Low-rolling_resistance_tires "Low-rolling resistance tires")
35. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-37)**
Chandler, David (9 February 2009). ["More power from bumps in the road"](https://web.mit.edu/newsoffice/2009/shock-absorbers-0209.html). Retrieved 8 October 2009.
36. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-38)** [Gas Saving and Emission Reduction Devices Evaluation \| Cars and Light Trucks \| US EPA](https://archive.today/20120729113626/http://www.epa.gov/otaq/consumer/reports.htm). Epa.gov. Retrieved 21 September 2011.
37. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-39)** [https://onfuel.appspot.com](https://onfuel.appspot.com/) keep track of fuel efficiency
38. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-40)**
["Anglian Water spot on with pressure test"](http://www.tyrepress.com/2015/10/anglian-water-spot-on-with-pressure-test/). *Tyrepress*. 29 October 2015. Retrieved 30 October 2015.
39. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-41)** [Chinese Fuel Economy Laws](http://www.treehugger.com/files/2005/07/chinese_fuel_ec.php). Treehugger.com. Retrieved 21 September 2011.
40. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-42)**
Cox, Lisa (30 March 2019). ["'Woefully dirty': Government accused over Australia's failure to cut vehicle emissions"](https://www.theguardian.com/environment/2019/mar/31/government-accused-australia-failure-cut-vehicle-emissions). *The Guardian*.
41. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-43)** [Vehicles & the Environment](http://www.infrastructure.gov.au/roads/environment/index.aspx). Infrastructure.gov.au. Retrieved 21 September 2011.
42. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-44)** [Information on Green Vehicle Guide Ratings and Measurement](https://web.archive.org/web/20110716024739/http://www.greenvehicleguide.gov.au/GVGPublicUI/home.aspx). Australian Department of Infrastructure and Transport
43. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-45)** [Green Vehicle Guide](http://www.greenvehicleguide.gov.au/) [Archived](https://web.archive.org/web/20060422230409/http://www.greenvehicleguide.gov.au/) 22 April 2006 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). Green Vehicle Guide. Retrieved 21 September 2011.
44. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-nrcan.gc.ca_46-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-nrcan.gc.ca_46-1)
["5-cycle testing"](https://www.nrcan.gc.ca/energy/efficiency/transportation/cars-light-trucks/buying/7495). *nrcan.gc.ca*. 30 April 2018.
45. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-47)** [Vehicle test cycles](http://herkules.oulu.fi/isbn9514269543/html/x787.html). Herkules.oulu.fi. Retrieved 21 September 2011.
46. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-48)**
["News & Events"](https://www.honda.de/cars/world-of-honda/news-events.html). *www.honda.de*. Retrieved 2 May 2023.
47. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-49)**
["2011 Honda CR-Z Specs and Features"](https://autos.msn.com/research/vip/Spec_Glance.aspx?year=2011&make=Honda&model=CR-Z). Retrieved 2 May 2023.
\[*[permanent dead link](https://en.wikipedia.org/wiki/Wikipedia:Link_rot "Wikipedia:Link rot")*\]
48. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-50)** [Guidance notes and examples](http://www.vca.gov.uk/additional/files/fcb--co2/enforcement-on-advertising/vca061.pdf) [Archived](https://web.archive.org/web/20080413221042/http://www.vca.gov.uk/additional/files/fcb--co2/enforcement-on-advertising/vca061.pdf) 13 April 2008 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). (PDF). Retrieved 21 September 2011.
49. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-51)** [Fuel Economy Label](http://www.dft.gov.uk/actonco2/index.php?q=fuel_economy_sticker) [Archived](https://web.archive.org/web/20080814112511/http://www.dft.gov.uk/ActOnCO2/index.php?q=fuel_economy_sticker) 14 August 2008 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). Dft.gov.uk. Retrieved 21 September 2011.
50. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-52)** [Vehicle Labelling](http://www.environ.ie/en/Environment/Atmosphere/ClimateChange/VehicleLabelling/) [Archived](https://web.archive.org/web/20080707012035/http://www.environ.ie/en/Environment/Atmosphere/ClimateChange/VehicleLabelling/) 7 July 2008 at the [Wayback Machine](https://en.wikipedia.org/wiki/Wayback_Machine "Wayback Machine"). Environ.ie (1 July 2008). Retrieved 21 September 2011.
51. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-53)**
["Regulation (EU) 2019/631 of the European Parliament and of the Council of 17 April 2019 setting CO2 emission performance standards for new passenger cars and for new light commercial vehicles, and repealing Regulations (EC) No 443/2009 and (EU) No 510/2011 (Text with EEA relevance.)"](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A32019R0631). [European Union](https://en.wikipedia.org/wiki/European_Union "European Union"). 25 April 2019. "Annex 1, Part A.6 NEDC2020, Fleet Target is 95 g/km. (45) Manufacturers whose average specific emissions of CO2 exceed those permitted under this Regulation should pay an excess emissions premium with respect to each calendar year."
52. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-54)**
["Why the EC figures do not represent true MPG"](https://www.honestjohn.co.uk/realmpg/why-are-the-ec-figures-so-optimistic-true-mpg/). *Honest John*. Retrieved 14 November 2015.
53. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-55)**
["Real Life Fuel Economy (MPG) Register"](http://www.honestjohn.co.uk/realmpg/). *Honest John*. Retrieved 14 November 2015.
54. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-56)**
["Cars and Garages: Diagnose Problems, Estimate Costs & Find Garages"](http://www.carsandgarages.co.uk/news/29-ASA-says-fuel-consumption-figures-are-mis). *carsandgarages.co.uk*.
55. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-57)**
Mike Millikin (28 September 2014). ["ICCT: gap between official and real-world fuel economy figures in Europe reaches ~38%; call to implement WLTP ASAP"](http://www.greencarcongress.com/2014/09/20140928-icct.html). [Green Car Congress](https://en.wikipedia.org/w/index.php?title=Green_Car_Congress&action=edit&redlink=1 "Green Car Congress (page does not exist)"). Retrieved 28 September 2014.
56. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-58)** [From laboratory to road: A 2018 update](https://www.theicct.org/publications/laboratory-road-2018-update) ICCT, 2019
57. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-JapTest01_59-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-JapTest01_59-1)
[Japan Automobile Manufacturers Association](https://en.wikipedia.org/wiki/Japan_Automobile_Manufacturers_Association "Japan Automobile Manufacturers Association") (JAMA) (2009). ["From 10•15 to JC08: Japan's new economy formula"](http://www.jama-english.jp/europe/news/2009/no_2/peternunn.html). News from JAMA. Retrieved 9 April 2012.
*Issue No. 2, 2009*.
58. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-JapTest02_60-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-JapTest02_60-1)
["Japanese 10–15 Mode"](https://www.dieselnet.com/standards/cycles/jp_10-15mode.php). Diesel.net. Retrieved 9 April 2012.
59. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-61)**
["Prius Certified to Japanese 2015 Fuel Economy Standards with JC08 Test Cycle"](http://www.greencarcongress.com/2007/08/prius-certified.html). [Green Car Congress](https://en.wikipedia.org/w/index.php?title=Green_Car_Congress&action=edit&redlink=1 "Green Car Congress (page does not exist)"). 11 August 2007. Retrieved 9 April 2012.
60. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-62)**
["Vehicle Fuel Economy Labelling – FAQs"](https://web.archive.org/web/20080710061145/http://www.eeca.govt.nz/transport/vehicle-fuel-economy/faqs.htm). Archived from [the original](http://www.eeca.govt.nz/transport/vehicle-fuel-economy/faqs.htm) on 10 July 2008. Retrieved 2 May 2023.
61. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-63)** [Frequently Asked Questions](https://www.fueleconomy.gov/feg/info.shtml#guzzler). Fueleconomy.gov. Retrieved 21 September 2011.
62. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-64)**
Steven Cole Smith (28 April 2005). ["2005 Pontiac GTO"](https://web.archive.org/web/20150511195355/http://www.cars.com/pontiac/gto/2005/reviews/?revid=47269). Orlando Sentinel via Cars.com. Archived from [the original](http://www.cars.com/pontiac/gto/2005/reviews/?revid=47269) on 11 May 2015. Retrieved 21 February 2011.
63. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA_cycles_65-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA_cycles_65-1)
["Dynamometer Driver's Aid"](https://web.archive.org/web/20140330111359/http://www.epa.gov/nvfel/testing/dynamometer.htm). US EPA. Archived from [the original](http://www.epa.gov/nvfel/testing/dynamometer.htm) on 30 March 2014. Retrieved 11 January 2011.
64. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-66)** [How the EPA Tests and Rates Fuel Economy](https://auto.howstuffworks.com/28004-epa-fuel-economy-explained1.htm). Auto.howstuffworks.com (7 September 2005). Retrieved 21 September 2011.
65. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-67)** [Gasoline Vehicles: Learn More About the Label](https://fueleconomy.gov/feg/label/learn-more-gasoline-label.shtml). Retrieved 10 July 2020.
66. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-68)** [Find a Car 1985 to 2009](https://www.fueleconomy.gov/feg/findacar.htm). Fueleconomy.gov. Retrieved 21 September 2011.
67. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-2008epa_test_69-0)**
["2008 Ratings Changes"](https://www.fueleconomy.gov/feg/fe_test_schedules.shtml). US EPA. Retrieved 17 April 2013.
68. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-70)**
US EPA United States Environmental Protection Agency. ["Basic Search"](https://web.archive.org/web/20170122021353/https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=35113&flag=1). Iaspub.epa.gov. Archived from [the original](https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=35113&flag=1) on 22 January 2017. Retrieved 1 September 2022.
69. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-71)** Roth, Dan. (1 October 2009) [REPORT: EPA planning to address outlandish fuel economy claims of electric cars](http://www.autoblog.com/2009/10/01/report-epa-planning-to-address-outlandish-fuel-economy-claims-o/). Autoblog.com. Retrieved 21 September 2011.
70. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-GCCEPAVolt_72-0)**
["Volt receives EPA ratings and label: 93 mpg-e all-electric, 37 mpg gas-only, 60 mpg-e combined"](http://www.greencarcongress.com/2010/11/volt-20101124.html#more). [Green Car Congress](https://en.wikipedia.org/w/index.php?title=Green_Car_Congress&action=edit&redlink=1 "Green Car Congress (page does not exist)"). 24 November 2010. Retrieved 24 November 2010.
71. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPAmpge_73-0)**
[US Environmental Protection Agency](https://en.wikipedia.org/wiki/US_Environmental_Protection_Agency "US Environmental Protection Agency") and [US Department of Energy](https://en.wikipedia.org/wiki/US_Department_of_Energy "US Department of Energy") (4 May 2011). ["2011 Chevrolet Volt"](https://www.fueleconomy.gov/feg/phevsbs.shtml). Fueleconomy.gov. Retrieved 21 May 2011.
72. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-NYTEPA_74-0)**
Nick Bunkley (22 November 2010). ["Nissan Says Its Electric Leaf Gets Equivalent of 99 M.P.G."](https://www.nytimes.com/2010/11/23/business/23leaf.html?_r=1&hpw) *The New York Times*. Retrieved 23 November 2010.
73. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA2013_75-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA2013_75-1) [***c***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA2013_75-2)
EPA (May 2011). ["Fact Sheet: New Fuel Economy and Environment Labels for a New Generation of Vehicles"](https://web.archive.org/web/20110529061246/http://www.epa.gov/otaq/carlabel/420f11017.htm). [US Environmental Protection Agency](https://en.wikipedia.org/wiki/US_Environmental_Protection_Agency "US Environmental Protection Agency"). Archived from [the original](http://www.epa.gov/otaq/carlabel/420f11017.htm) on 29 May 2011. Retrieved 25 May 2011.
*EPA-420-F-11-017*
74. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-GCC2013_76-0)**
["EPA, DOT unveil the next generation of fuel economy labels"](http://www.greencarcongress.com/2011/05/felabel-20110525.html). [Green Car Congress](https://en.wikipedia.org/w/index.php?title=Green_Car_Congress&action=edit&redlink=1 "Green Car Congress (page does not exist)"). 25 May 2011. Retrieved 25 May 2011.
75. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-77)**
["Not All Fuel Efficiency Is Equal: Understanding the Miles-Per-Gallon Illusion"](https://web.archive.org/web/20140115125904/http://www.businessweek.com/articles/2014-01-14/not-all-fuel-efficiency-is-equal-understanding-the-miles-per-gallon-illusion). *Bloomberg.com*. 14 January 2014. Archived from [the original](http://www.businessweek.com/articles/2014-01-14/not-all-fuel-efficiency-is-equal-understanding-the-miles-per-gallon-illusion) on 15 January 2014. Retrieved 11 November 2014.
76. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-78)**
["The MPG Illusion"](http://blogs.berkeley.edu/2013/06/03/the-mpg-illusion/). 3 June 2013. Retrieved 11 November 2014.
77. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-79)**
John M. Broder (25 May 2011). ["New Mileage Stickers Include Greenhouse Gas Data"](https://www.nytimes.com/2011/05/26/business/energy-environment/26label.html?_r=1&emc=eta1). *The New York Times*. Retrieved 26 May 2011.
78. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-80)**
["CAFE Overview: "What is the origin of CAFE?""](https://web.archive.org/web/20090203174614/http://www.nhtsa.dot.gov/portal/site/nhtsa/template.MAXIMIZE/menuitem.43ac99aefa80569eea57529cdba046a0/?javax.portlet.tpst=f2d14277f710b755fc08d51090008a0c_ws_MX&javax.portlet.prp_f2d14277f710b755fc08d51090008a0c_viewID=detail_view&javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken&itemID=199b8facdcfa4010VgnVCM1000002c567798RCRD&viewType=standard#6). NHTSA. Archived from [the original](http://www.nhtsa.dot.gov/portal/site/nhtsa/template.MAXIMIZE/menuitem.43ac99aefa80569eea57529cdba046a0/?javax.portlet.tpst=f2d14277f710b755fc08d51090008a0c_ws_MX&javax.portlet.prp_f2d14277f710b755fc08d51090008a0c_viewID=detail_view&javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken&itemID=199b8facdcfa4010VgnVCM1000002c567798RCRD&viewType=standard#6) on 3 February 2009. Retrieved 9 July 2008.
79. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-NYTApril18_81-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-NYTApril18_81-1)
[Tabuchi, Hiroko](https://en.wikipedia.org/wiki/Hiroko_Tabuchi "Hiroko Tabuchi") (2 April 2018). ["Calling car pollution standards 'too high,' EPA sets up fight with California"](https://www.nytimes.com/2018/04/02/climate/trump-auto-emissions-rules.html). *The New York Times*.
80. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-ELQSept03_82-0)**
Giovinazzo, Christopher (September 2003). ["California's Global Warming Bill: Will Fuel Economy Preemption Curb California's Air Pollution Leadership"](https://scholarship.law.berkeley.edu/cgi/viewcontent.cgi?referer=https://www.google.com/&httpsredir=1&article=1735&context=elq). *Ecology Law Quarterly*. **30** (4): 901–902\.
81. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-NYTDec07_83-0)**
Tabuchi, Hiroko (19 December 2007). ["EPA Denies California's Emissions Waiver"](https://www.nytimes.com/2007/12/19/washington/20epa-web.html). *The New York Times*.
82. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-WaPoJan08_84-0)**
Richburg, Keith (3 January 2008). ["California Sues EPA Over Emissions Rules"](https://www.washingtonpost.com/wp-dyn/content/article/2008/01/02/AR2008010202833.html). *The Washington Post*.
83. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-GTMJune09_85-0)**
Wang, Ucilia (30 June 2009). ["EPA grants California emissions waiver"](https://www.greentechmedia.com/articles/read/epa-grants-california-emissions-waiver). *Greentech Media*.
84. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-86)**
["Obama Administration Finalizes Historic 54.5 MPG Fuel Efficiency Standards"](https://obamawhitehouse.archives.gov/the-press-office/2012/08/28/obama-administration-finalizes-historic-545-MPG-fuel-efficiency-standard). White House. 28 August 2012. Retrieved 28 November 2019.
85. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-87)**
Fraser, Laura (Winter 2012–2013). "Shifting Gears". *NRDC's OnEarth*. p. 63.
86. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-NYT2018_88-0)**
Tabuchi, Hiroko (5 April 2018). ["Quietly, Trump officials and California seek deal on emissions"](https://www.nytimes.com/2018/04/05/climate/trump-california-emissions.html). *The New York Times*.
87. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-89)**
Phillips, Anna M. (21 February 2019). ["Trump administration confirms it has ended fuel-economy talks with California"](https://www.latimes.com/politics/la-na-pol-california-fuel-economy-trump-20190220-story.html). *Los Angeles Times*. Retrieved 11 May 2019.
88. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-90)**
Associated Press (6 January 2021). ["For first time in 5 years, US gas mileage down, emissions up"](https://www.ocregister.com/2021/01/06/for-first-time-in-5-years-us-gas-mileage-down-emissions-up). *Orange County Register*. Retrieved 7 January 2021.
89. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-91)**
["Trump rollback of mileage standards guts climate change push"](https://news.yahoo.com/trump-rollback-mileage-standards-guts-151423701.html). *Yahoo News*. 31 March 2020. Retrieved 2 May 2023.
90. **[^](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-92)**
Kaufman, Alexander; D'Angelo, Chris (20 December 2021). ["EPA Reverses Trump's Fuel Mileage Rules On New Cars"](https://www.huffpost.com/entry/epa-reverses-trump-fuel-mileage-rules_n_61c0b34de4b061afe395ec7f). *HuffPost*. Retrieved 20 December 2021.
91. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-:0_93-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-:0_93-1)
Hilgers, Michael (2021). *Commercial Vehicle Technology: Fuel consumption and consumption optimization*. Wilfried Achenbach. Berlin. [ISBN](https://en.wikipedia.org/wiki/ISBN_\(identifier\) "ISBN (identifier)")
[978-3-662-60841-8](https://en.wikipedia.org/wiki/Special:BookSources/978-3-662-60841-8 "Special:BookSources/978-3-662-60841-8")
. [OCLC](https://en.wikipedia.org/wiki/OCLC_\(identifier\) "OCLC (identifier)") [1237865094](https://search.worldcat.org/oclc/1237865094).
`{{cite book}}`: CS1 maint: location missing publisher ([link](https://en.wikipedia.org/wiki/Category:CS1_maint:_location_missing_publisher "Category:CS1 maint: location missing publisher"))
92. ^ [***a***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA_CO2_est_94-0) [***b***](https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles#cite_ref-EPA_CO2_est_94-1)
["Emission Facts: Average Carbon Dioxide Emissions Resulting from Gasoline and Diesel Fuel"](https://web.archive.org/web/20090228190530/http://www.epa.gov/oms/climate/420f05001.htm). *Office of Transportation and Air Quality*. [United States Environmental Protection Agency](https://en.wikipedia.org/wiki/United_States_Environmental_Protection_Agency "United States Environmental Protection Agency"). February 2005. Archived from [the original](http://www.epa.gov/OMS/climate/420f05001.htm) on 28 February 2009. Retrieved 28 July 2009.
- [Real fuel consumption by user reports](https://www.auto-abc.eu/info/real-fuel-consumption)
- [Model Year 2014 Fuel Economy Guide](https://www.fueleconomy.gov/feg/pdfs/guides/FEG2014.pdf) , [U.S. Environmental Protection Agency](https://en.wikipedia.org/wiki/U.S._Environmental_Protection_Agency "U.S. Environmental Protection Agency") and [U.S. Department of Energy](https://en.wikipedia.org/wiki/U.S._Department_of_Energy "U.S. Department of Energy"), April 2014.
- [Fuel Efficiency in Electric, Hybrid and Petrol Cars – Model Year 2019](https://ecohungry.com/electric-and-petrol-cars-fuel-efficiency/)
- [Fuel Consumption Calculator Online](https://www.fuelcostcalculator.online/) |
| Shard | 152 (laksa) |
| Root Hash | 17790707453426894952 |
| Unparsed URL | org,wikipedia!en,/wiki/Fuel_economy_in_automobiles s443 |