updated 12/11/2006 6:12:55 PM ET 2006-12-11T23:12:55

Car buyers will face a new form of sticker shock when they browse dealer lots next year: Mileage estimates will be down, reflecting the way people actually drive.

The Environmental Protection Agency Monday issued new testing procedures that will cause fuel economy estimates on the stickers of new vehicles to drop an average of 12 percent for city driving on most 2008 model year vehicles and 8 percent for highway driving.

Highly fuel-efficient vehicles are expected to see the largest slide, with ratings for city driving dropping by as much as 30 percent and highway estimates falling 25 percent from current levels.

Mileage estimates for gas-electric hybrids probably will be 20 to 30 percent lower for city driving and 10 to 20 percent lower on the highway, the agency said.

The changes respond to consumer complaints that fuel economy estimates are frequently less than advertised. EPA’s new system will take into account data from vehicle tests designed to more accurately assess high-speed driving, rapid acceleration, the use of air conditioning and driving in cold temperatures.

“EPA’s new fuel economy sticker ensures American motorists won’t be stuck with higher-than-anticipated charges at the pump,” EPA Administrator Stephen L. Johnson said in a statement.

The agency said no test can precisely predict the fuel economy of a vehicle because driving behaviors and conditions vary. But the test methods will help bring the estimates on the window stickers closer to what drivers achieve on the road.

Stickers also will be upgraded to include fuel cost information, a graphic for comparing the fuel economy of different vehicles and a Web site address for more information.

Test results will not be used to determine whether automakers comply with laws requiring the U.S. fleet to have an average fuel economy of 27.5 miles per gallon for cars and 21 mpg for sport utility vehicles, pickup trucks and vans.

Those requirements are found in the Corporate Average Fuel Economy program, which is run by the Transportation Department and has separate regulations to determine fuel economy.

Russell Long of Bluewater Network, a San Francisco-based environmental group that sought the changes, said the new testing procedures would help motorists save money and reduce pollution.

But Long said the “new numbers will expose how far short American passenger vehicles are from the 27.5 mpg that Congress intended them to achieve over 30 years ago.”

Consumers have long complained that their vehicle’s fuel economy is often much less than the estimates on the sticker, and Congress mandated the changes in its energy bill in 2005.

EPA’s test methods were last revised in 1984. The rules issued Monday were proposed in January and implemented after public comment.

For the first time the agency will require labeling of medium-duty vehicles, which weigh between 8,500 and 10,000 pounds, including SUVs and vans. Automakers will be required to post the labels on the vehicles beginning with the 2011 model year.

Toyota and Ford said they did not have revised fuel economy estimates for 2008 models of their hybrid vehicles. The top-selling Toyota Prius reports an EPA estimate of 60 mpg in the city and 51 mpg on the highway while the Ford Escape hybrid, the first hybrid SUV on the market, gets an estimated 36 mpg in the city and 31 mpg on the highway.

Auto industry officials noted that mileage estimates differ depending on vehicle speeds, quick stops and starts, routine maintenance and whether the vehicle is hauling cargo in the trunk.

“Even with the new labels, mileage will vary,” said Charles Territo, a spokesman for the Alliance of Automobile Manufacturers. The trade group released a new Web site detailing the changes dubbed mileagewillvary.com.

The industry group said 2007 will be a transition year for the labels, with some of the new estimates appearing on dealer lots in the next few months. Consumers should compare the mileage estimates on 2007 models to other 2007 vehicles and 2008 vehicles to other models from that year, they said.

“Consumers deserve the government’s best efforts when it comes to compiling the information they see on the label of new vehicles,” said Robert L. Darbelnet, president of the industry group. “That has not been the case, and EPA is moving to correct the situation.”

© 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Discuss:

Discussion comments

,

Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments

Data: Latest rates in the US

Home equity rates View rates in your area
Home equity type Today +/- Chart
$30K HELOC FICO 4.95%
$30K home equity loan FICO 5.19%
$75K home equity loan FICO 4.58%
Credit card rates View more rates
Card type Today +/- Last Week
Low Interest Cards 13.40%
13.40%
Cash Back Cards 17.92%
17.91%
Rewards Cards 17.12%
17.11%
Source: Bankrate.com