NASHVILLE -- U.S. production of Nissan's Leaf electric vehicle has resulted in improved EPA fuel economy numbers for the car.
According to the EPA, the U.S.-built 2013 Leaf -- which has no fuel tank -- gets a miles per gallon equivalent (MPGe) of 115 in combined city and highway driving. Last year the almost identical 2012 Leaf earned a 99 MPGe for combined city and highway driving.
The production move from Japan to Nissan's plant in Smyrna, Tenn., this year gave the automaker a chance to make a small number of midcycle engineering changes, company spokesman Brian Brockman says.
The 2013 model has an enhanced regenerative braking system and contains a few spots of improved aerodynamics. The new model has a drag coefficient of 0.28, compared with 0.29 last year, thanks in large part to a tweak in the front bumper fascia.
Nissan also trimmed 129 pounds through changes in parts, such as a smaller charging unit. But Nissan contends the improved EPA numbers are still slightly lower than they ought to be because of the agency practice of averaging the two driving modes.
The company and EPA fuel-economy regulators have wrestled with how to create an accurate consumer comparison between gasoline-engine autos and battery-powered vehicles.
"The EPA has instituted a new testing methodology, which makes comparing the performance of the 2013 Leaf to previous models difficult," Brockman says.
Last year the lower EPA number used a test that measured the Leaf's range with a 100 percent-charged battery.
This year the EPA's estimates averaged together two Leaf driving modes. The first tested the car with a 100 percent battery charge, as it did last year. The second tested the car's battery-saving Long Life Battery Mode, which prevents the car from being charged beyond 80 percent of its capacity. Using only the 100 percent charge, he says, would have yielded higher MPGe numbers.