11-16-2008, 01:19 PM
Join Date: Nov 2004
2016 Cayman GT4
Your Mileage May Still Vary
DRIVERS have complained for years that their cars could not attain the optimistic fuel economy figures listed on the window sticker. But since the Environmental Protection Agency has changed the way it calculates fuel economy, many consumers are saying their mileage is even better than the estimates, according to a recent survey by J. D. Power & Associates, the market research firm.
This has pocketbook implications because some people use the government’s mileage estimates to try to calculate how much they will spend on gasoline during the time they own a vehicle. And getting more than you expected is always better than getting less.
The E.P.A. revised its standards in 1984, but many drivers found their actual mileage fell short of those estimates. The disparity was due, in part, to the fact that the federal testing standards no longer accurately represented driving conditions in the United States. So, starting with 2008 models, the agency again changed the way it calculated fuel economy figures.
J. D. Power looked at the new E.P.A. estimates and compared them with the mileage that consumers reported getting in the company’s 2008 Initial Quality Study earlier this year. The information came from more than 81,500 people with 2008 vehicles. That information was compared with results from the 2007 Initial Quality Study. The idea was to see how close the consumer-stated mileage came to the federal estimate before and after the changes.
In the 2007 study, the mileage drivers said they were getting was, on average, 97 percent of the E.P.A. estimate. But in the 2008 study, the stated mileage was 105 percent of the estimate.
“In 2007, consumers would get 3 percent less than they would have expected on average,” Mike Marshall, J. D. Power’s director of automotive emerging technologies, said in an e-mail message. “But in 2008, they would get 5 percent more, thus going from unmet expectations to exceeded expectations.”
It is difficult to know the reality, he said, because the J. D. Power survey depends on people’s perceptions of their mileage over the first 120 days they owned their vehicle. The E.P.A. testing is done using strict scientific methods.
Still, finding out you spent 5 percent less on gasoline than you thought is a more pleasant surprise than discovering you have to pay 3 percent more because you underestimated your fuel costs based on the E.P.A. estimate, Mr. Marshall said in a telephone interview.
Before the agency adopted the new method, owners of hybrids were often among the most disappointed that they couldn’t achieve the optimistic estimates on the window sticker. Now, more hybrid owners said they were getting fuel economy closer to what the E.P.A. predicted, or even more.
The Toyota Prius is an example. In the 2007 survey, consumers reported getting only 81 percent of the E.P.A.’s estimates, which were 60 m.p.g. in the city and 51 m.p.g. on the highway.
In the 2008 survey, drivers reported getting 94 percent of the new estimates, which are 48 m.p.g. in the city and 45 on the highway.
“There is still a gap, but it’s much better,” Mr. Marshall said.