«*EPA
Un.iudSwti.-s Office of Transportation EPA420-F-04-053
A!wncr'lt*'!"'i P'"U'1'' "" and Air Quality October 2004
TTw's facf s/?eef 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 effi-
ciency 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.
-------
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). 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
Information
Ss Sn The
Fuel
Economy
Guide and
on The
Fuel
Economy
Label?
economy which don't occur during laboratory testing, such as cold
temperature, aggressive driving, excessive use of power-hungry accesso-
ries, 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 / [(salesl/FEl)+ (sales2/FE2) + ...+ (salesn/
FEn)]
The calculation for combined fuel economy weights the city at 55 per-
cent 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
Premium Unleaded Gasoline
Diesel Fuel
CNG (Gasoline equivalent)
E85 Ethanol Fuel
LPG (Propane)
Hydrogen
Electricity
$1.80 per gallon
$1.95 per gallon
$1.55 per gallon
$1.05 per gallon
$1.65 per gallon
$1.40 per gallon
$7.20 per kilogram
$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. fuel economy, gov.
-------
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 ob-
tained 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 adminis-
ters 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 com-
ply 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 rela-
tive 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.
-------
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 regula-
tions, 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 summariz-
ing 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
------- |