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EPAfs 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 Corporate 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 ap-
proximately 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 impor-
tance 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.
SEFtt
United States
Environmental Protection
Agency
Office of Transportations and Air Quality
EPA420-F-06-074
December 2006
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Fuel Economy Labels and Fuel Economy Guide
Once a year, EPA and DOE publish the Fuel Economy Guide listing the fuel economy esti-
mates (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. 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 (how-
ever, 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, Michi-
gan.
How are Vehicles Tested?
Vehicles are driven over identical driving patterns by professional drivers in controlled labo-
ratory 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.
There are two types of tests that are conducted: city and highway tests.
The city test is approximately 11 miles long and simulates a stop and go trip with an aver-
age speed of about 20 miles per hour (mph).The trip lasts 31 minutes and has 23 stops.
About 18 percent of the time is spent idling (as in waiting for traffic lights). A short freeway
driving segment is included in the test. The engine is initially started after being parked
overnight.
The highway test simulates a 10 mile trip with an average speed of 48 mph. The vehicle is
started "hot" and there is very little idling and no stops.
How Are the Label Estimates Calculated?
Fuel economy estimates are calculated from the emissions generated during the tests
EPA's Fuel Economy Programs
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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 econo-
my.
After the vehicles have been tested, the results are adjusted downward to account for con-
ditions that occur on the road that can affect fuel economy which don't occur during labora-
tory testing, such as cold temperature, aggressive driving, excessive use of power-hungry
accessories, among others. The city is adjusted downward by 10 percent, and the highway
by 22 percent.
The equation for calculating the city or highway average fuel economy, given in miles per
gallon (mpg), is:
FEave = (total sales /[(sales1/FE1)+ (sales2/FE2) + ...+ (salesn/FEn)]
The calculation for combined fuel economy weights the city at 55 percent and the highway
at 45 percent using the following equation:
FEcomb = 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 projected annual fuel costs as determined from the com-
bined city and highway fuel economy, assuming 15,000 miles traveled per year and using
estimated fuel costs (provided by the Department of Energy) from the following table (for
2007 model year vehicles):
Regular Unleaded Gasoline $2.65 per gallon
Premium Unleaded Gasoline $2.85 per gallon
Diesel Fuel $2.65 per gallon
CNG (Gasoline equivalent) $1.45 per gallon equivalent
E85 Ethanol Fuel $2.20 per gallon
LPG (Propane) $1.70 per gallon
Hydrogen $5.85 per kilogram
Electricity $0.10, 0.15 per kilowatt-hour
The fuel prices were determined in advance to allow time for printing labels and the Fuel
Economy Guide. For more recent fuel cost estimates using current fuel prices, visit www.
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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 avail-
able to consumers. The Guide is also available online at www.fueleconomy.gov.
Corporate Average Fuel Economy (CAFE)
Corporate Average Fuel Economy (CAFE) is the required average fuel economy for a ve-
hicle 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 ad-
ministers the testing program which generates the fuel economy data and determines the
procedures for calculating the fuel economy values for CAFE. The National High way 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. More information about CAFE can be found on NHTSAs web site at http://
Www.nhtsa.dot.gov/portal/site/nhtsa/menuitem.d0b5a45b55bfbe582f57529cdba046a0/.
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 ve-
hicle 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 as-
signed to each vehicle. Vehicles rated higher than others are designed to emit fewer pol-
lutants 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 stan-
dards, 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.
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The Green Vehicle Guide also identifies the cleanest, most fuel efficient vehicles with a
" S rm art Ways rm" logo. More information about SmartWay vehicles is found at http://www.
epa.gov/greenvehicles/about.htm.
Gas Guzzler Tax
The Gas GuzzlerTax 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 differ-
ent from the fuel economy estimates provided in the Fuel Economy Guide. The tax is col-
lected 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). Information on Gas GuzzlerTax: www.epa.gov/otaq/cert/mpg/guzzler/index.htm.
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
• Information on vehicle fuel economy, advanced
technoogy, and possible tax incentives, including a down loadable version of
the Fuel Economy Guide:
www.fueleconomy.gov
• Information on CAFE, including CAFE standards, NHT SAs annual report
summarizing the fuel economy performance of the current fleet, rulemaking
activities, and fines collected:
www.nhtsa.dot.gov/portal/site/nhtsa/menuitem.
dOb5a45b55bfbe582f57529cdba046aO/
• The IRS's Gas GuzzlerTax form (IRS Form 6197):
www.irs.gov/pub/irs-pdf/f6197.pdf
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