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Program

Overview

Office of Transportation

and Air Quality

EPA420-F-04-053

October 2004

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 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.
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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 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). A vehicle from each of these groups

with the highest projected sales must be tested.

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.

After the vehicles have been tested, the results are adjusted downward to

account for conditions that occur on the road that can affect fuel

What

Vehicles

Are

Tested?

How are

vehicles

tested?

How Are

the Label

Estimates

Calculated?
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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 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))

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 2005 model year vehicles):

Regular Unleaded Gasoline $1.80 per gallon

Premium Unleaded Gasoline $1.95 per gallon

Diesel Fuel $1.55 per gallon

CNG (Gasoline equivalent) $1.05 per gallon

E85 Ethanol Fuel $1.65 per gallon

LPG (Propane) $1.40 per gallon

Hydrogen $7.20 per kilogram

Electricity $0.10, 0.15 per kilowatt-hour

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.fueleconomy.gov.

What

Information

Is In The

Fuel

Economy

Guide and

on The

Fuel

Economy

Label?
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Corporate Average Fuel Economy

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 gross vehicle weight rating (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

(NHTSA), which is part of DOT, is responsible for establishing and

amending the CAFE standards for 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.
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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 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 EPA’s 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 NHTSA’s annual report summarizing the fuel economy performance of the current fleet, rulemaking

activities, and fines collected: http://www.nhtsa.dot.gov/cars/rules/

cafe/

• The IRS’s Gas Guzzler Tax form (IRS Form 6197): http://

www.irs.gov/pub/irs-pdf/f6197.pdf