WASHINGTON — Tighter new EPA guidelines issued on Monday to automakers for conducting vehicle testing are designed to "ensure that consumers have reliable fuel economy information," the federal agency said in a statement.
The new guidelines, which will go into effect beginning with the 2017 model year, come after several automakers have had to restate mpg ratings for certain models.
The guidelines are aimed at getting more accurate fuel economy numbers that consumers can trust. Some car owners gripe that their actual mileage does not match figures advertised by automakers.
Automakers received the new guidelines in a 10-page EPA document.
The document spells out testing requirements in great detail, including the acceptable level of wear on the tires, how vehicles should be "warmed up" prior to testing and the type of test road or test track conditions that are necessary for an accurate test.
"This guidance also introduces a new method that allows the EPA to examine road load forces over a broad range of vehicle speeds to better align with current testing methods," the EPA said. "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 the EPA's historic greenhouse gas emissions standards for cars and light trucks achieve the environmental results promised to the American public."
Road load tests determine the impact of aerodynamic drag and tire rolling resistance on gas mileage. Each year, the EPA identifies a number of production vehicles for audit testing to measure whether the actual road load value matches what automakers reported to the agency.
Currently, the road load test is measured at 50 mph. Automakers must measure the results at all speeds up to 70 mph under the new guidelines.
Last year, the EPA fined Hyundai and Kia a record-setting penalty for overstating fuel economy ratings. In June 2014, Ford apologized to consumers and revised the fuel economy rating on six new cars, including the 2014 Ford Fiesta.
Edmunds says: This latest move by the EPA should bolster consumer confidence in the reliability of the fuel economy estimates they see on the window stickers of new cars and trucks in dealer showrooms.