Regulatory Announcement

EPA Issues New Test Methods for Fuel 

Economy Window Stickers

EPA420-F-06-069

December 2006

Office of Transportation and Air Quality

The U.S. Environmental Protection Agency (EPA) is finalizing new test methods for calculating the fuel economy 

estimates, which are posted on window stickers of new cars and 

trucks. These estimates help consumers compare the fuel economy 

of different vehicles for both city and highway driving. This new 

rule makes three important changes.

First, EPA’s new methods will bring the miles per gallon (mpg) 

estimates closer to consumers’ actual fuel economy by including 

factors such as high speeds, quicker accelerations, air conditioning 

use, and driving in cold temperatures. The new estimates will 

take effect with model year 2008 vehicles (available in dealer 

showrooms in 2007).

Second, for the first time, EPA will require fuel economy labels 

on certain heavier vehicles up to 10,000 pounds (lb) gross vehicle 

weight, such as larger SUVs and vans. These vehicles had been 

exempt because they exceeded the previous weight limit of 8,500 

lb. Manufacturers will be required to post fuel economy labels on 

these vehicles beginning with the 2011 model year.

Third, to convey fuel economy information to the public more 

effectively, EPA is changing the design and content of the window 

sticker. The new label design will make it easier for consumers 

to compare fuel economy when shopping for new vehicles. New 

labels will be required on vehicles manufactured after September 

1, 2007.
Regulatory Announcement

EPA Issues New Test Methods for Fuel 

Economy Window Stickers

Background

Existing Tests and Methods

Fuel economy estimates have been provided to consumers since the 1970s as a tool 

to help shoppers compare the fuel economy of different vehicles. Currently, EPA relies 

on data from two laboratory tests to determine the city and highway fuel economy 

estimates. The test methods for calculating these estimates were last revised in 1984, 

when the fuel economy derived from the two tests were adjusted downward – 10 

percent for city and 22 percent for highway -- to more accurately reflect driving styles 

and conditions.

The city and highway tests are currently performed under mild climate conditions (75 

degrees F) and include acceleration rates and driving speeds that EPA believes are 

generally lower than those used by drivers in the real world. Neither test is run while 

using accessories, such as air conditioning. The highway test has a top speed of 60 

miles per hour, and an average speed of only 48 miles per hour.

Since the mid-1990s, EPA’s emissions certification program has required the use 

of three additional tests which capture a much broader range of real-world driving 

conditions, including high-speed, fast-acceleration driving, the use of air conditioning, 

and colder temperature operation (20 degrees F). These conditions affect not only the 

amount of air pollutants a vehicle emits, but also a vehicle’s fuel economy. However, 

these tests were not required to measure fuel economy.

The New Methods to Determine Fuel Economy Estimates

For the first time, the EPA fuel economy estimates will use vehicle-specific data from 

tests designed to replicate three real-world conditions, which can significantly affect 

fuel economy: high speed/rapid acceleration driving, use of air conditioning, and cold 

temperature operation. Previously, these conditions were accounted for by across-theboard adjustments, rather than by vehicle-specific testing.

EPA’s new fuel economy estimates will also reflect other conditions that influence fuel 

economy, like road grade, wind, tire pressure, load, and the effects of different fuel 

properties. The fuel economy for each vehicle model will continue to be presented to 

consumers on the label as city and highway MPG estimates.

In 2011, manufacturers will need to perform additional cold temperature, air 

conditioning, and/or high speed/rapid acceleration driving tests for those vehicles most 

sensitive to these conditions. However, in order to provide consumers with better 

fuel economy estimates sooner, EPA will use new calculation methods that capture 

these driving conditions. These estimates will begin with model year 2008 vehicles. 

The interim period from model year 2008 to model year 2011 will give manufacturers 

enough time to plan for this additional testing, while providing consumers with 

estimates that capture more realistic driving conditions.
Regulatory Announcement

EPA Issues New Test Methods for Fuel 

Economy Window Stickers



How the New Test Methods Will Affect Fuel Economy 

Estimates

Under EPA’s new methods, the new fuel economy estimates for most vehicles will be 

lower. This is not because auto makers have designed the same vehicles to be less fuel 

efficient – it is because our new test methods take into account factors that have been 

missing or not fully accounted for in the current tests. Because some vehicles are more 

sensitive to these factors than others, the impact of the changes will vary from vehicle 

to vehicle.

Compared to today’s estimates, the city mpg estimates for the manufacturers of most 

vehicles will drop by about 12 percent on average, and by as much as 30 percent for 

some vehicles. The highway mpg estimates will drop on average by about 8 percent, 

and by as much as 25 percent for some vehicles.

In vehicles that achieve generally better fuel economy, such as gasoline-electric hybrid 

vehicles, new city estimates will be about 20 to 30 percent lower than today’s labels, 

and new highway estimates will be 10 to 20 percent lower. The nature of current 

hybrid technology -- the addition of a battery as a second source of on-board power, 

sophisticated control systems, and sometimes a smaller engine – makes a hybrid’s fuel 

economy more sensitive to certain factors, such as colder weather and air conditioning 

use. However, many hybrid models will remain among the most fuel-efficient vehicles 

on the market.

Since driving behaviors and conditions vary, there is no test that can perfectly predict 

the fuel economy that every driver will get. With any estimate, there will always be 

times when a driver’s actual fuel economy will be higher or lower. However, EPA’s new 

test methods will do a better job of bringing the estimates on the window sticker closer 

to people’s real-world fuel economy experience.

Laboratory Tests Reflect Real-World Conditions

It is essential that EPA’s fuel economy estimates continue to be derived from controlled, 

repeatable laboratory tests to enable a standardized or “level playing field,” comparison 

between all vehicle models. However, the underlying calculations to determine the 

estimates are based on data from real-world driving behavior and conditions. Laboratory 

testing also preserves EPA’s ability to confirm the results of manufacturers’ testing.

Auto makers will continue to be responsible for performing the fuel economy 

testing and calculating the label mpg estimates. EPA will continue to confirm the 

manufacturers’ test results by performing audit testing at its National Vehicle and Fuel 

Emissions Laboratory in Ann Arbor, Michigan.
Regulatory Announcement

EPA Issues New Test Methods for Fuel 

Economy Window Stickers



Larger SUVs and vans required to have fuel economy 

labels

Because the U.S. Department of Transportation (DOT) has recently ruled to integrate 

medium-duty passenger vehicles (MDPVs), including large SUVs and vans, into the 

Corporate Average Fuel Economy (CAFE) program starting in 2011, EPA must now 

include these vehicles in the fuel economy labeling program. Thus, EPA will be requiring 

fuel economy labeling of certain passenger vehicles up to 10,000 lb gross vehicle 

weight rating (GVWR). These vehicles used to be exempt because they weighed more 

than the previous cut-off of 8,500 lb. Vehicle manufacturers will be required to post fuel 

economy labels on MDPVs beginning with the 2011 model year.

Fuel Economy Label Design

To more clearly convey fuel economy information to consumers, EPA has revised 

the design and content of the fuel economy window sticker that appears on new 

automobiles.

The new label features more prominent fuel cost information, a user-friendly graphic 

for comparing the fuel economy of different vehicles, clearer text, and a Web site 

address for more information. Since the new label design will be required on vehicles 
Regulatory Announcement

EPA Issues New Test Methods for Fuel 

Economy Window Stickers

manufactured on September 1, 2007, or later, manufacturers will be phasing in the new 

design during the 2008 model year. For model years 2008 and 2009, the label will also 

state that estimates reflect new EPA test methods beginning with 2008 models. More 

information on the revised window sticker is available on EPA’s Web site at:

www.epa.gov/fueleconomy/label.htm

No Impact on CAFE

EPA’s rule has no impact on the CAFE program, which is administered by DOT’s 

National Highway Traffic and Safety Administration (NHTSA). 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 regulations concerning the test methods and procedures to determine the fuel 

economy values under the CAFE program. For more information on CAFE, please visit 

NHTSA’s Web site at:

http://www.nhtsa.dot.gov/portal/site/nhtsa/menuitem.d0b5a45b55bfbe582

f57529cdba046a0/

For More Information

You can access documents on this rulemaking on EPA’s Office of Transportation and Air 

Quality Web site at:

www.epa.gov/fueleconomy/regulations.htm

For further information, please contact the Assessment and Standards Division at:

U.S. Environmental Protection Agency

Office of Transportation and Air Quality

2000 Traverwood Drive

Ann Arbor, MI 48105

Voicemail: (734) 214-4636

E-mail: asdinfo@epa.gov