The Fisker Karma’s 20 M.P.G. Sticker: A Scarlet Letter?

With its range-extender gasoline engine engaged, the Fisker Karma plug-in hybrid was rated this week by the Environmental Protection Agency at just 20 miles per gallon. The E.P.A. figure was first reported by the blog

In the ensuing blowback, some critics concluded that the luxury sport sedan, which was not yet certified by the California Air Resources Board for sale in that primary E.V. market, would be a “fuel economy flop.”

Like the bankrupt solar company Solyndra, Fisker also received a loan from the Energy Department, $528.7 million, feeding the critics’ grist.

According to the E.P.A., the Karma has a purely electric range of 32 miles, in the vicinity of the Chevrolet Volt’s 35-mile rating, and a mileage equivalent in battery mode of 52 MPGe, compared with the Volt’s 93 MPGe.

“Over all, we’re pleased,” said Roger Ormisher, a spokesman for Fisker, when asked in a telephone interview how the automaker reacted to the E.P.A. rating.

Plug-in hybrids are new to market, as are the E.P.A.’s MPGe ratings, which also apply to purely electric cars. Dual-mode hybrids like the Karma can be driven with or without the gas engine running, so a driver’s behavior strongly influences a car’s performance. Owners with shorter commutes are likely to use the Karma mostly in all-electric mode, Mr. Ormisher said, returning the approximate per-gallon economy of a Toyota Prius. In 100-mile daily commutes, with the gas engine engaged, the car would disappoint would-be hypermilers.

Still, the ability of MPGe to convey an E.V.’s equivalent gasoline fuel economy to shoppers is not entirely proven, as the new metric was just introduced in the spring. The E.P.A. offers this definition:

“The mpg-equivalent metric expresses the energy consumption of a nongasoline vehicle in terms of how many miles the vehicle could go on gasoline if it used the same amount of gasoline energy as it used of the nongasoline fuel energy. For example, a gallon of gasoline has the energy equivalent of 33.7 kilowatt-hours of electricity. An E.V. that uses 33.7 kilowatt-hours to drive 100 miles will use the energy equivalent of one gallon of gasoline, and therefore would have an MPGe of 100 miles per gallon of gasoline equivalent.”

Charles Griffith, director of the climate and energy program at the Ecology Center, a nonprofit environmental advocacy organization in Ann Arbor, Mich., thinks that Karma owners will try to drive electric.

“I think most people are going to strive to be in the electric mode as much as possible,” he said. “We’re going to need a lot of data gathering in the first few years of electric and plug-in hybrid cars to see how people actually drive these vehicles.”

Mr. Griffith said that the E.P.A. might have purposely rated the Karma conservatively at 20 m.p.g. in gas mode. “It’s unfortunate if it discourages some people from purchasing these vehicles, but a bigger concern would be promising more miles per gallon and then disappointing drivers.” In his review of the Chevrolet Volt for The Times, for example, Lawrence Ulrich observed fuel economy of 44 m.p.g., besting the E.P.A. rating by a full nine m.p.g.

John DeCicco, a senior lecturer at the University of Michigan who developed a competing E.V. metric called AutoEcoRating, said that the Karma should be compared to similar high-performance cars. “You don’t want to compare it to a Nissan Leaf,” he said in a telephone interview.

The Karma’s 6.3-second zero-to-60 time, while quick, does not position it anywhere near supercar range.

As a marketplace offering, Mr. Ormisher compared the Karma to the 2012 Porsche Panamera, which achieved a slightly better combined fuel-economy rating of 24 m.p.g. The Panamera is roughly $20,000 cheaper, however, so to maintain its comparative advantage in this not-so-hypothetical marketplace, a Karma would have to rely on its purely electric range and comparative rarity on the road.