Dottie Love does her homework before buying a car. Last year, she began researching the Toyota Prius, a gas-electric hybrid, in hopes it would save her some gas money on her 100-mile-a-day commute – but soon was faced with conflicting data.

Consumer Reports said that the car would get an average of 50 miles per gallon, while the Environmental Protection Agency said the car would get closer to 60 mpg.

Conversations with Prius owners online confirmed whom she should trust.

“Nobody gets 60 miles per gallon,” said Love, who eventually bought the car and reliably gets 50.

Sticker shock at the pump has more drivers thinking about fuel economy. As Americans get used to gasoline prices above $2 a gallon, new car buyers are looking more closely at miles-per-gallon data.

But those who want an accurate estimate of mileage may be disappointed by some fuzzy math that goes into the calculations.

Mileage estimates for city and highway driving provided by the EPA have been routinely inflated because of an unrealistic methodology used since the EPA began testing vehicles in 1974, according to critics such as AAA.

An Environmental Protection Agency mileage sticker is shown on a Toyota Corolla at Vandergriff Toyota in Arlington, Texas. Consumers are becoming more interested in the fuel efficiency of vehicles as gasoline prices rise.

“When a consumer is told, ‘Your mileage may vary,’ it probably should say, ‘Your results will vary,’ ” said Susan Pikrallidas, AAA vice president of public affairs.

The EPA puts new models on an enormous treadmill and runs them for different periods of time. For the highway estimate, the EPA simulates a 10-mile trip with an average speed of 48 mph.

Now the EPA is re-evaluating its test to make the agency’s mileage estimates more accurate. Recommendations for updating the process are expected this year. The newly designed test likely will incorporate several common driving habits that burn extra gas, including using air conditioning and driving in congested areas, according to the EPA.

Government crash-test ratings also are making their way onto some vehicle stickers. Honda announced in June that it voluntarily will include the information on stickers for all 2006 Honda and Acura models. Legislation has been introduced in Congress to require that the information be included on all new cars.

A recent CNN/USA Today/Gallup survey shows that more than half of Americans are thinking of buying a more fuel-efficient car in the future.

When Peter Stamps shopped for a new vehicle late last year, a sport-utility vehicle seemed to fit one of his primary needs. He wanted something big enough to accommodate his wife and two children.

But the engineer quickly ruled out the option.

“I was looking for something that had decent mileage,” Stamps said.

Stamps eventually bought a Chrysler Town and Country. The mileage sticker at the dealership said the minivan would get 18 mpg in city driving and 27 mpg on the highway.

Stamps said he hasn’t driven it enough to determine the vehicle’s actual mileage.

“We’re planning on taking a long drive. We’ll see if it lives up to its word then,” he said.

Experts say that fuel efficiency isn’t yet steering big changes in the auto market.

Art Spinella, of CNW Marketing Research, said that some people were moving away from gas-guzzling SUVs, but that the impact of high gas prices remained limited.

For more than a decade, Spinella has been analyzing what people look for in a new car. Among 52 attributes, fuel economy has climbed more than any other feature in the last two years.

Then again, it still places 23rd.

“It’s lower than cupholders,” Spinella said. “It still hasn’t risen to the value of performance, which is around 11.”

The two most important attributes: quality and driver visibility.

Gas prices would need to reach $2.80 a gallon, and stay that high for at least six months, before many drivers would change their buying habits, Spinella said.

In the meantime, some are trying to conserve.

Many families are relegating the SUV to secondary-vehicle status, only using it when something needs to be towed, Spinella said.

Kyle Bennett, of Plano, Texas, owns a Hummer H2, the tanklike vehicle that has become the symbol of fuel inefficiency. The 2004 model averages 9.6 mpg, according to www.trucks.about.com.