New Test Methods for Fuel Economy Window Stickers Proposed

In an effort to provide consumers with more real-world fuel economy information when shopping for cars, SUVs, and pick-up trucks, EPA is proposing new methods to determine the city and highway miles-per-gallon (mpg) estimates that appear on the window stickers. The new methods will take effect for model year 2008 vehicles, which will generally be available for sale in fall of 2007, the agency stated on Jan. 10.

EPA's new fuel economy estimates will include vehicle-specific data from tests designed to replicate three factors that can greatly affect fuel economy: high speed/rapid acceleration, use of air conditioning, and cold temperature operation.

EPA also is proposing an across-the-board-adjustment to better account for other conditions that can affect fuel economy but that aren't included in the tests, such as road grade, wind, tire pressure, load, and the effects of different fuel properties.

Under the new methods, the city mpg estimates for most vehicles would drop 10 percent to 20 percent from today's labels, depending on the vehicle. The highway mpg estimates would generally drop 5 percent to 15 percent.

Even with improved estimates, actual fuel economy will vary since no test can ever account for all individual driving styles, vehicle maintenance practices and road conditions, officials said.

Changes were last made in 1985. The proposed changes will improve the estimates to better reflect real-world driving conditions, such as higher speed limits, greater traffic congestion and more use of power-hungry accessories, such as air conditioning, according to the agency.

To more clearly convey fuel economy information to consumers, EPA also is proposing to change the design and text of the window sticker itself. Four options are under consideration.

None of the proposed changes affect the Corporate Average Fuel Economy (CAFE) program, which is administered by the Department of Transportation. There are separate requirements for the test methods and procedures for determining fuel economy values under CAFE.

The proposal and information about how to submit comments can be found at

This article originally appeared in the 01/01/2006 issue of Environmental Protection.

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