Edmunds.com/Inside Line (Enlarge photo)

19/09/2008 15:30. It might look like an ordinary S-Class, but make no mistake, because the 2010 Mercedes-Benz S400 BlueHybrid represents a major step in the development of the hybrid luxury car.

This prototype is Mercedes-Benz's belated answer to the Lexus LS 600h L — a gasoline-electric hybrid that delivers a combined 299 horsepower along with average fuel consumption just shy of 30 mpg. It also heralds some of the most advanced battery technology ever applied to a series production car.

Don't hold your breath waiting for it, though. With Mercedes-Benz yet to complete development, North American sales aren't planned to get under way until September 2009.

You'll have already heard about the 2010 Mercedes-Benz S400 BlueHybrid from last year's Frankfurt Motor Show, where it was hailed as the forerunner... // Edmunds.com/Inside Line