's Fuel Economy Programs
This fact sheet describes the U.S. Environmental Protection
Agency's (EPA) Fuel Economy Program. EPA is responsible for
providing the fuel economy data that is used by the U.S. Department
of Energy (DOE) to publish the annual Fuel Economy Guide, by the
U.S. Department of Transportation (DOT) to administer the Cor-
porate Average Fuel Economy (CAFE) program, and by the Internal
Revenue Service (IRS) to collect Gas Guzzler taxes.
Introduction
Fuel economy, or gas mileage, continues to be a major area of public and policy
interest for several reasons. Passenger vehicles account for approximately 40
percent of all U.S. oil consumption, so increasing energy efficiency helps reduce our
dependence on imported oil and enhances the nation's energy security. Likewise,
it helps conserve our fossil resources for future generations. Passenger vehicles also
contribute about 20 percent of all U.S. carbon dioxide emissions, so increasing fuel
efficiency helps reduce greenhouse gas emissions. Finally, the more miles a car gets
per gallon of gasoline, the more money the owner saves on fuel costs. Given the
importance of fuel economy, the federal government administers three programs
to provide information to consumers about fuel economy and to encourage the
production of fuel efficient vehicles.
Fuel Economy Labels and Fuel Economy Guide
Once a year, EPA and DOE publish the Fuel Economy Guide listing the fuel
economy estimates (expressed in miles per gallon) of new passenger vehicles. The
Fuel Economy Guide is published and distributed by DOE based on EPA's data. The
fuel economy estimates listed in the guide are based on laboratory testing performed
by the auto manufacturers and EPA.
What Vehicles Are Tested?
Not every vehicle is tested for fuel economy. Instead, manufacturers are required to
split each model into smaller groups, based upon the various options available that
can impact fuel economy (such as vehicle weight, transmission type and engine size).
A vehicle from each of these groups with the highest projected sales must be tested.
Office of Transportation and Air Quality
United States
Environmental Protection EPA420-F-07-066
A9encv October 2007
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Also, passenger cars and light trucks with a gross vehicle weight rating (GVWR) greater than
8,500 pounds are exempt from fuel economy requirements, and are not tested for fuel economy
(however, they are still subject to Federal emission requirements.)
Manufacturers test all the vehicles at their laboratories. EPA confirms about 10-15 percent of
the vehicles at its National Vehicles and Fuel Emission Laboratory in Ann Arbor, Michigan.
How a re Vehicles Tested?
Vehicles are driven over identical driving patterns by professional drivers in controlled
laboratory conditions on a dynamometer, which is like a treadmill for cars. The conditions that
occur during driving, such as wind drag and inertia are accounted for on the dynamometer. Prior
to 2008 model year vehicles, there were two types of tests that were conducted to determine the
city and highway estimates: The city test and the highway test. Beginning with 2008 model
year vehicles, data from five different tests are used to determine these estimates: FTP test,
Highway test, High Speed test, Air Conditioning test and Cold Temperature test. A description
of the details of these five tests is in the table below. The key elements of each test is shown in
bold:
Driving
Schedule
Attributes
Trip Type
Top Speed
Average
Speed
Max.
Acceleration
Simulated
Distance
Time
Stops
Idling time
Engine
Startup*
Lab
temperature
Vehicle air
conditioning
Test Schedule
City
Low speeds
in stop-and-
go urban
traffic
56 mph
20mph
3.3 mph/sec
11 mi.
31 min.
23
18% of time
Cold
Highway
Free-flow
traffic at
highway
speeds
60 mph
48 mph
3.2 mph/sec
10 mi.
12.5 min.
None
None
Warm
High Speed
Higher speeds;
harder
acceleration &
braking
80 mph
48 mph
8.46 mph/sec
8 mi.
10 min.
4
7% of time
Warm
68-86°L
Off
Off
Off
AC
AC use under
hot ambient
conditions
54.8 mph
22 mph
5.1 mph/sec
3.6 mi.
9.9 min.
5
19% of time
Warm
95°L
On
Cold Temp
City test w/
colder outside
temperature
56 mph
20 mph
3.3 mph/sec
11 mi.
31 min.
23
18% of time
Cold
20°L
Off
* A vehicle's engine doesn't reach maximum fuel efficiency until it is "warm.
EPA's Fuel Economy Programs
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How Are the Label Estimates Calculated?
Fuel economy estimates are calculated from the emissions generated during the tests using a
carbon balance equation. We know how much carbon is in the fuel, so by precisely measuring
the carbon compounds expelled in the exhaust we can calculate the fuel economy.
For pre-2008 model year vehicles, the city and highway tests were used to determine city and
highway fuel economy, respectively. The results of the tests were adjusted downward to account
for typical road conditions that can affect fuel economy, such as higher speeds, cold temperature,
and use of air conditioning. The city results were adjusted downward by 10 percent, and the
highway results by 22 percent.
For 2008 and later model year vehicles, the fuel economy label estimates are determined by
either performing the entire set of five tests on the test vehicle, and using that data to calculate
city and highway estimates, or, at the manufacturer's option until the 2011 model year, by
applying mathematical equations to the basic data from the city and highway tests to derive
estimates that simulate the effects of all five test cycles.
Combined fuel economy is determined by weighting the city at 55 percent and the highway at
45 percent using the following equation:
FEcombined = 1 / (( .55 / city FE) + (.45 / hwy FE))
What Information Is In The Fuel Economy Guide and on The Fuel
Economy Label?
The fuel economy city and highway estimates are printed in the Fuel Economy Guide and
posted on the window sticker labels of all new cars and light trucks. Also included on the labels
and in the Guide are the estimated annual fuel costs as determined from the combined city and
highway fuel economy, assuming 15,000 miles traveled per year and using the following fuel
price projections obtained from the Department of Energy):
Regular Unleaded Gasoline $2.80 per gallon
Premium Unleaded Gasoline $3.00 per gallon
Diesel Fuel $2.80 per gallon
E85 $2.60 per gallon
LPG $2.10 per gallon
CNG $1.65 per gallon equivalent
Electricity $0.10, 0.20 per kilowatt-hour
Hydrogen $6.30 per kg
The fuel prices are determined in advance to allow time for printing labels and the Fuel
Economy Guide. For more recent annual fuel cost estimates using current fuel prices, visit
www.fueleconomy.gov. The Fuel Economy Guide is published and distributed to dealerships
across the United States. New car dealers are required to have copies of the Guide available to
consumers. The Guide is also available online at www.fueleconomy.gov.
EPA's Fuel Economy Programs
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Beginning with 2008 model year vehicles, EPA has redesigned the fuel economy label to better
present the fuel economy information to consumers who are shopping at dealers' lots. Improved
features include more details about how annual fuel costs are estimated, an easy-to-understand
graph showing how the fuel economy for that vehicle compares to all others within its class, and
a web link to go to for further information
Corporate Average Fuel Economy (CAFE)
Corporate Average Fuel Economy (CAFE) is the required average fuel economy for a vehicle
manufacturer's entire fleet of passenger cars and light trucks manufactured for sale in the United
States for each model year. There are separate average fuel economy standards for passenger
cars and light trucks. Light trucks include those with a gross vehicle weight rating (GVWR)
of 8,500 pounds or less. CAFE values are obtained using the same test data generated by the
fuel economy tests used to determine the fuel economy estimates for the Guide and labels, but
the test results are not adjusted to account for real-world conditions. Instead, the results from
the city and highway tests are combined. EPA administers the testing program which generates
the fuel economy data and determines the procedures for calculating the fuel economy values
for CAFE. The National Highway Traffic and Safety Administration (NHTSA), which is part
of DOT, is responsible for establishing and amending the CAFE standards for light trucks.
Congress sets the CAFE standards for cars. EPA reports the CAFE results for each manufacturer
to NHTSA annually, and NHTSA determines if the manufacturers comply with the CAFE
standards and assesses penalties as required.
Green Vehicle Guide
Every year since 2000, EPA publishes emissions information for the new model year cars and
light trucks on its Green Vehicle Guide Web site at www.epa.gov/greenvehicles. This user-
friendly site is designed to help consumers identify the cleanest, most efficient vehicle that
meets their needs. It provides consumers with the opportunity to compare the relative emissions
performance of vehicles by means of the 0-10 emissions rating assigned to each vehicle. Vehicles
rated higher than others are designed to emit fewer pollutants such as carbon monoxide,
nitrogen oxides, hydrocarbons and particulate matter. Vehicles can be viewed individually or by
class, such as SUVs, sedans, or pickups.
The emissions ratings are based on the EPA emission standards the vehicle was certified to meet.
Because manufacturers can choose from a complex set of emission standards, it is not always
easy to understand them. The Green Vehicle Guide "demystifies" these standards, and allows
consumers to see that they may have a choice to buy a cleaner, more efficient vehicle, regardless
of the size, type or style they are interested in.
The Green Vehicle Guide also identifies the cleanest, most fuel efficient vehicles with a
"SmartWay" logo. To view more information about SmartWay vehicles, visit www.epa.gov/
greenvehicles/Aboutratings.do. EPA has recently revised the format of the Green Vehicle
Guide to allow provide users with more options for searching and sorting data. Now it's easier
than ever to find the greenest vehicle that fits your needs!
EPA's Fuel Economy Programs
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Gas Guzzler Tax
The Gas Guzzler Tax is imposed on manufacturers of new model year cars (not minivans, sport
utility vehicles or pick-up trucks) that fail to meet the minimum fuel economy level of 22.5
mpg. The tax is intended to discourage the production and purchase of fuel inefficient vehicles.
The fuel economy figures used to determine the tax are based on combined city and highway
fuel economy that is unadjusted for real-world conditions, and thus is different from the fuel
economy estimates provided in the Fuel Economy Guide. The tax is collected by the Internal
Revenue Service and normally paid by the manufacturer or importer after production has
ended for the model year and is based on the total number of gas guzzler vehicles which were
introduced into commerce in the United States. The amount of the tax paid is displayed on the
vehicle's fuel economy label (the window sticker on new cars).
For More Information
You can access additional information about these programs at the following web sites:
• Information on EPA's Fuel Economy Program, including regulations, test data,
and consumer tips:
www.epa.gov/fueleconomy/index.htm
• Information on vehicle fuel economy, advanced technology, and possible tax
incentives, including a downloadable version of the Fuel Economy Guide:
www.fueleconomy.gov
• Information on CAFE, including CAFE standards, NHTSA's annual report
summarizing the fuel economy performance of the current fleet, rulemaking
activities, and fines collected:
Www.nhtsa.dot.gov/portal/site/nhtsa/menuitem.d0b5a45b55bfbe582f57529cdba046a0/
• Information about the Gas Guzzler Tax is available at:
www.epa.gov/fueleconomy/guzzler/index.htm
• The IRS's Gas Guzzler Tax form (IRS Form 6197): www.irs.gov/pub/irs-pdf/f6197.pdf
EPA's Fuel Economy Programs
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