Mileage Rules Bump Car Costs, Savings at the Pump

But don’t expect to find a sea of 55-mpg cars at your local auto mall come 2025. As we’ve explained before, CAFE mileage numbers mean little to consumers. Today’s EPA window stickers are subject to a litany of adjustments to emulate real-world driving conditions. CAFE numbers, in contrast, stem from 1970s-era fuel tests. The EPA says 54.5 mpg should mean real-world gas mileage of about 39 mpg, but vehicle engineer Jim Kliesch of the Union of Concerned Scientists said he expects an average window label of 36 to 37 mpg.

Still, that’s a big improvement over today’s real-world mileage — about 22 mpg, the EPA reports, or 5 mpg short of present-day CAFE.

The National Highway Traffic Safety Administration estimates the new standards will add about $2,200 to the cost of a 2025 car, but by our math, five years’ typical ownership at current gas prices should return nearly $3,750 in fuel savings versus today. NHTSA, meanwhile, estimates up to $6,600 in total fuel savings over the life of the car — “a hell of a lot more” than you pay up front, Kliesch says.

UCS’ annual Automaker Rankings, which rate environmental performance, put Honda at the top for the fifth year running, but Toyota and Hyundai have made recent strides. All three should have little problem meeting the 2025 CAFE, but Kliesch says 2011 could be a bump in the road for Toyota and Honda. The earthquake and tsunami in Japan cut supplies of fuel-efficient cars, which are typically heavy on Japanese parts. Fuel-efficient commuters from Toyota and Honda — the Toyota Yaris, Corolla and Prius, and the Honda Civic, Fit and Insight — are down 11.8% through October.

Honda, for one, appears undeterred. “We are not in the background going, ‘I don’t know how we’re going to [make CAFE],'” U.S. chief John Mendel told us at the L.A. Auto Show. “You can build a vehicle that gets 54.5 miles per gallon, but it’s got to be something that somebody wants to buy to be effective.”