When the Fisker Karma concept debuted, it was billed as a luxury plug-in hybrid electric vehicle with the performance of a sports car. Last week, the EPA rated the Fisker Karma at 52 miles per gallon-equivalent (mpg-e) in combined driving, according to AutoblogGreen. This number combines both electric-only range and the fuel economy delivered by the Karma’s four-cylinder gasoline engine.

Not only is this rating lower than other plug-in hybrids, but it falls short of Fisker’s 67.2 mpg-e predictions. By comparison, the 2011 Chevrolet Volt has a rating of 60 mpg-e, according to the EPA, while the Toyota Prius Plug-in nets 87 mpg-e.

In the explanation of the Karma’s mpg-e rating, the EPA stated that the PHEV will net 32 miles of all-electric range, but when the gas motor kicks in, it will only net 20 mpg. The Chevrolet Volt has an EPA-rated 35-mile electric range, and gets 37 mpg using its gas engine/generator. The Prius Plug-in will drive for about 15 miles using only electric power, and nets 49 mpg in hybrid mode.

Though the Fisker Karma’s mpg-e, electric range and mpg ratings are significantly lower than the Volt and the Prius Plug-in, shoppers should keep in mind that the Karma is much heavier than both of these vehicles due to its luxurious interior, and its 404 horsepower is about three times the power that the Prius Plug-in puts to the ground.  

Though the Karma isn’t living up to Fisker’s fuel economy expectations, analysts say the EPA tests still benefit the automaker, since cars can’t be sold in the U.S. until they’ve been rated by the EPA. Fisker says Karma deliveries can start this week, AutoObserver reports. “Fisker told AutoObserver that it had more than 200 of the U.S. cars awaiting delivery to customers.”

Fortunately, some industry commentators estimate that the Fisker Karma’s high price tag and luxury cachet mean that most of its buyers won’t be deterred by the news. “Given the Karma's market slot as a high-performance exotic aimed at buyers who likely already have Corvettes, Ferraris and other high-end, high-performance vehicles in their garages, the fuel economy numbers aren't likely to put a damper on sales, but they could fuel critics in Congress who have opposed federal aid to nascent manufacturers of advanced technology cars,” writes Inside Line.

The Fisker Karma starts at $96,000, and is on sale now.

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