We reported recently that the EPA had gotten back with a pretty miserable 52 mpg rating for the Fisker Karma extended-range EV. Now Fisker has received its rating from the European certification agency Technischer Üeberwachungs Verein (TÜV), and it has come out at 112 mpg. That's a huge difference, which calls into question the ways rating agencies test extended-range EVs. There is always a difference in the mpg ratings of European and U.S.-tested vehicles, but this gap is so large as to render these numbers meaningless to the consumer. Why did one agency achieve 112 miles per gallon while the other only managed half that efficiency?
As we are not conspiracy theorists, we think it must have to do with how the vehicles are being driven and what is considered normal conditions for testing. The Fisker Karma is a series plug-in hybrid, which is a system that can be tuned for optimum efficiency at different speeds. If the Fisker performs optimally at higher speeds like the Chevy Volt extended-range EV, then testing it with more time at higher speeds would drastically improve its efficiency. That seems to be what happened. The TUV rated the Fisker Karma at 98 mpg in the city and 118 on the highway, which indicates this European test may favor high-speed driving. But that city rating is still nearly double what the EPA managed to eke out from the Karma at lower speeds, which likely indicates that the EPA is testing to how Americans drive their cars (i.e. more aggressively), while the TUV is testing for optimal efficiency. Whatever happened to create these grossly divergent numbers, we’re glad the Karma was able to prove itself in one ratings test. Rest assured you do not need to go buy your Karma in Europe to get good fuel efficiency. You just need to retrain yourself to drive like a European.