The Environmental Protection Agency has issued new guidelines to automakers for conducting fuel economy testing. The move comes after a number of automakers had to restate miles-per-gallon (mpg) ratings for some of their popular vehicles.
The new guidelines detail how vehicles should be prepared before testing takes place, like what is an acceptable amount of wear on the tires and how vehicles should be broken in before testing, according to an EPA press release.
Road load tests, which are used to determine the impact of aerodynamic drag and tire rolling resistance of gas mileage, have also been changed. Currently, automakers can measure results going 50 miles per hour. Now companies must measure the results at all speeds up to 70 mph.
"We think this guidance will result in more accurate fuel economy numbers that consumers can trust," said Byron Bunker, director of compliance for the E.P.A.'s Office of Transportation and Air Quality to The New York Times.
The updated guidelines should come as no surprise, since the agency said last year it was considering issuing new formal regulations to cover mileage labeling by companies. Instead, the EPA decided to issue new guidelines.
It usually takes EPA around two to three years to write new legal binding mandates, according to
"You've had disappointment from consumers who expect the mileage to be what is on the window sticker, and who find things are off by not just a little, but by a lot," said Karl Brauer, an analyst with Kelley Blue Book to the Times. "There isn't much patience for it by consumers, and it's why we see the government taking a tougher stance than we used to."
The new rules should lead to lower fuel economy ratings if automakers haven't complied previously with the test.
Automakers are under pressure to get their average corporate fuel economy to a federally mandated 54.5 mpg by 2025, up from 25 mpg that vehicles average today.
"Releasing this guidance is another step in enhancing our oversight of our fuel economy labels to ensure that consumers have reliable fuel economy information, and that EPA's historic greenhouse gas emissions standards for cars and light trucks achieve the environmental results promised to the American public," the agency said in its release.