Last year, three automakers had to reduce the official Environmental Protection Agency fuel economy rating for some of their vehicles: Mini, Ford and Mercedes. That was the second time that Ford had to adjust the MPG numbers and all of these changes came after the big Kia-Hyundai problems with exaggerated numbers back in 2012. To prevent these sorts of embarrassing changes from happening in the future, the EPA issued new rules today describing how to test new vehicles starting with model year 2017. You can read the entire letter the EPA sent to automakers, which contains details on how many miles the test vehicle should have on it, how old the tires should be and more.

You might remember that the main problem with the vehicles that needed to have their MPG numbers changed was difficulty getting the road-load force correct. The EPA defines road-load force as the force "imparted on a vehicle while driving at constant speed over a smooth level surface from sources such as tire rolling resistance, driveline losses, and aerodynamic drag." Getting this number right is key for ending up with a miles per gallon number on the window sticker that is closer to the real-world fuel efficiency buyers will see once they drive the car off the lot. The EPA issued a statement that says the new guidance document, "provides the automotive industry with detailed information about how EPA conducts audits of road load force values," and we can only hope that the days of big fines for incorrect MPG numbers are over.
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Today, EPA issued a guidance document that provides the automotive industry with detailed information about how EPA conducts audits of road load force values, a critical input into fuel economy and greenhouse gas emissions calculations for cars and trucks. Each year, EPA identifies a number of production vehicles for audit testing to measure whether the actual road load value matches what automakers reported to EPA. Today's guidance clarifies EPA's criteria and methods for conducting these tests. This guidance also introduces a new method that allows EPA to examine road load forces over a broad range of vehicle speeds to better align with current testing methods. 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.

EPA Says Gas Mileage Numbers Inflated on 4 Mini Cooper Models

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