New vehicle buyers could soon face a new kind of sticker shock — lower estimated mileage — under a proposal unveiled by the Environmental Protection Agency.
If finalized after a public comment period, new vehicle fuel economy stickers will show most 2008 models getting 10 percent to 20 percent less mileage in city driving and 5 percent to 15 percent less in highway use.
Gasoline-electric hybrids will be affected even more, with ratings for city driving decreasing an average of 20 percent to 30 percent.
The long-awaited proposal is the first attempt in 20 years to alter the formula used by the EPA to estimate new vehicle fuel economy. That formula determines what fuel economy estimates appear on the stickers of every new car in showrooms across the United States.
“Since the time of the last revisions to EPA's methods for measuring fuel economy (1985), many conditions have changed — speed limits are higher, congestion has increased, and more vehicles are equipped with power-hungry accessories, like air conditioning,” the EPA said in a statement ahead of the announcement. “All of these factors will impact a vehicle's actual fuel economy.”
Environmentalists petitioned for the change, arguing that the existing formula inflates estimates because it is based on outdated driving patterns.
Currently, the EPA relies on data from two lab tests for the city and highway estimates. They’re done in mild conditions, when the temperature is 75 degrees, using top highway speeds of 60 mph and average speeds of 48 mph. Those conditions, the EPA acknowledges, are “generally lower than those experienced by drivers in the real world.”
‘More realistic’ factors
The proposed new formula would take into account “more realistic” factors already used to measure vehicle emissions:
- Driving at high-speed, defined as 80 mph or more;
- Aggressive driving, defined as accelerating at more than 3.3 miles per second;
- Driving with the air-conditioning on;
- Driving in cold temperatures.
The formula would also “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.”
EPA administrator Stephen Johnson said Tuesday that the formula is intended “to empower consumers with the most accurate information possible about a vehicle’s fuel economy,” including more details about the effects of “power-hungry accessories” used to lower windows, adjust seats or even play DVDs while driving.
“They can be confident those estimates more closely reflect real-world conditions,” he said.
Fred Webber, president of the Alliance of Automobile Manufacturers, said the industry supports the EPA’s proposal.
AAA — formerly the American Automobile Association — joined the EPA in making the announcement. “Consumers want to know that the information they see on a government-sanctioned label reasonably reflects what they will experience on the road,” said AAA president Robert Darbelnet.
Won’t apply to fleet rules
Bluewater Network, which petitioned the EPA to change its testing procedures in 2002, mostly welcomed the changes. “This has been a long time coming,” said Danielle Fugere, the group’s global warming campaign director.
But the new formula would not be used to gauge compliance with government regulations requiring automakers to produce fleets averaging at least 27.5 mpg for cars and 21 mpg for light trucks.
EPA Administrator Stephen Johnson said the Corporate Average Fuel Economy program run by the Transportation Department uses separate requirements for determining fuel economy.
Dan Becker, director of the Sierra Club’s global warming program, said that because the rules for complying with the CAFE standards aren’t changing, “the bottom line here is that this will have zero effect on oil savings or environmental impact.”
Background and instructions for commenting during a 60-day feedback window are online at www.epa.gov/fueleconomy/.