The Frankfurt Auto Show is still a month away, but that hasn't stopped the car companies from dropping previews and tip-offs of new concepts they have planned for the show. Mercedes-Benz will have one of the biggest presentations at the event, showcasing no less than 18 new models and concepts cars, and the underlying theme for the show will be its new green initiative.

One of the concepts it has planned will be a 'radical' proposal for a large luxury car labelled the F700. Though this doesn't sound very green, the concept will feature Mercedes' new 1.8L turbocharged DiesOtto engine. The tiny motor is said to deliver an amazing 238hp and 295ft-lb. of torque, while returning fuel consumption of around 39 mpg in a large S-class saloon.

Other cars planned for the show include the new C-Class estate, more Bluetec diesel cars and the automaker's new electric hybrid range.

[Source: 4Car]