Office of Transportation EPA420-F-05-045
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and Air Quality October 2005
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Program
Overview
EPA's Fuel Economy and
Emissions 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 approxi-
mately 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 about20 percent of all U.S.
carbon dioxide emissions, so increasing fuel efficiency helps reduce green-
house 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 produc-
tion of fuel efficient vehicles.
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What
Vehicles
Are
Tested?
How are
vehicles
tested?
How Are
the Label
Estimates
Calculated?
Fuel Economy 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.
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). Avehicle from each of these groups with
the highest proj ected 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 (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 Emissions
Laboratory in Ann Arbor, Michigan.
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. 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 average 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.
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.
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What
Information
Ss Sn The
Fuel
Economy
Guide and
on The
Fuel
Economy
Label?
After the vehicles have been tested, the results are adjusted downward to
account for conditions that occur on the road that can affect fuel economy
which don't occur during laboratory 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 per-
cent.
The equation for calculating the city or highway average fuel economy, given
in miles per gallon (mpg), is:
FEave = (total sales / [(salesl/FEl)+ (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))
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 combined 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 2006
model year vehicles):
Regular Unleaded Gasoline
Premium Unleaded Gasoline
Diesel Fuel
CNG (Gasoline equivalent)
E85EthanolFuel
LPG (Propane)
Hydrogen
Electricity
$2.20 per gallon
$2.40 per gallon
$2.05 per gallon
$1.25 per gallon equivalent
$2.00 per gallon
$1.65 per gallon
$5.80 per kilogram
$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.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 on-line at www.fnelecononiy.gov.
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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 for each model year. It applies to passenger cars and light trucks with a
GVWR of 8,500 pounds or less manufactured for sale in the United States.
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 (NHTS A),
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 NHTS A annually, and
NHTS A determines if the manufacturers comply with the CAFE standards
and assesses penalties as required. More information about CAFE can be
found at http://www.nhtsa.dot.gov/portal/site/nhtsa/
menuitem.dOb5a45b55bfbe582f57529cdba046aOA
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 con-
sumers 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
paniculate 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.
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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 different from the fuel economy values
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 EPAs Fuel Economy Program, including regulations, test
data, and consumer tips: www.epa.gov/fueleconomy
• 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: http://www.nhtsa.dot.gov/portal/site/nhtsa/
menuitem.dOb5a45b55bfbe582f57529cdba046aO/
• The IRS's Gas Guzzler Tax form (IRS Form 6197): www.irs.gov/pub/irs-
pdf7f6197.pdf
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