EPA: Our Fuel Economy Test Is Accurate for Hybrids

The U.S. Environmental Protection Agency says its test procedure for determining fuel economy is accurate for hybrid powertrains.

Christopher Grundler, director of EPA's Office of Transportation and Air Quality, tells Automotive News that the agency confirmed the accuracy of its methodology this summer.

The problem, Grundler says, lies not with the test but with an old EPA rule that allows carmakers to apply fuel economy results for one model to another with the same weight and powertrain.

EPA's assertion follows claims to the contrary from Ford Motor Co., which suggested earlier this month there is an "Industrywide issue" for the agency's test as applied to hybrids.

The question came to a head last December after owners and Consumer Reports magazine complained that the fuel economy of hybrid C-Max MPVs came nowhere near the vehicle's claimed 47-mpg city/highway/combined EPA rating. The agency's online owner poll indicates a real-life average of 39 mpg. Two weeks ago Ford lowered the car's rating to 43 mpg.

EPA concluded earlier this summer that Ford didn't actually test the C-Max hybrid's fuel economy. Instead, the company simply applied results for the Fusion hybrid, a sedan that weighs about the same and uses the same powertrain. AN notes that EPA has allowed the practice for decades to save carmakers the expense of testing multiple models that are virtually identical except for badging.

Grundler says the agency rule needs to be revised because powertrains are increasingly shared with significantly different types of vehicles. He tells AN the agency has not indicated when it might change the protocol.