Measuring fuel consumption in the upcoming generation of plug-in hybrid cars is not a straightforward process, as we’ve said before. Depending on the driving cycle and how often they’re recharged with electricity, their miles per gallon can range to infinity.
 
But such claims sound preposterous and may only damage automakers credibility, such marketing campaign in which  General Motors the upcoming Chevrolet Volt.
 
So it’s refreshing to see an emerging automaker make a more realistic claim, based on a standard set by the Society of Automotive Engineers (SAE). Fisker Automotive, which plans to  introduce the Karma  plug-in hybrid electric sedan next year, says the car will get 67 mpg based on the SAE test. (GM says its tests of the Volt were based on a new Environmental Protection Agency standard that has not been made public. However, government sources have told us the new EPA standard is based on the same SAE standard cited by Fisker.)
 
In price, the Fisker Karma is likely to compete with cars like the Mercedes-Benz S-Class and Lexus LS 600h. At Fisker’s claimed 67 mpg, the Karma would achieve a 75 percent reduction in fuel consumption and CO2 emissions compared with those cars. And it would be cleaner and more efficient than today’s best hybrids.
 
Like the Volt, the Karma’s fuel economy will depend entirely on how often it is recharged electrically and how it is driven.
 
Fisker also released some other detailed specifications for the Karma: It will have a 22 kwh battery capable of taking the car 50 miles on electricity between recharges. (A turbocharged 2.2-liter gasoline engine will kick in for longer trips.) The battery pack will produce 200 kw (about 268 hp). Fisker calls electric mode Stealth. Combining the engine and the electric motor (in Sport mode) yields a total of 403 horsepower.
 
All these numbers sound impressive. But we’ll have to wait until the Karma goes on sale to verify their accuracy. At least they don’t seem as wildly out of reach as those of GM.
 
-- Eric Evarts