The Frankfurt Auto Show this year is all about green cars: highly fuel efficient clean diesels, electric cars, and plug-in hybrids. It's where the German automakers offer up their sexiest concept cars.
So the photos of the eagerly awaited Mercedes-Benz "Vision" concept car are a bit of a shock: It looks identical to a standard 2010 Mercedes-Benz S-Class with a fancy white and silver paint job.
But it's the mechanical parts that matter; the Vision S500 is what Mercedes-Benz feels a plug-in hybrid S-Class luxury sedan would be like. It follows the lead of the amazing 2007 Vision F700 concept, a full-size four-door sedan with S-Class performance and Toyota Prius fuel economy.
The new concept has up to 18.5 miles of electric range. After that, a V6 (no details given) combines with a 60-hp electric motor to run as a conventional hybrid. Acceleration is said to be 5.5 seconds from 0 to 62 mph.
Gas mileage is quoted as 73.5 mpg, though you should take that number with a grain of salt. The fuel efficiency of plug-in hybrids varies with how the car is used. (Ditto GM's claim of 230 city mpg for its 2011 Chevrolet Volt, as well as the 67-mpg claim for the 2010 Fisker Karma.)