Autocar reports that Mercedes is planning to produce a hybrid version of its S-class sedan. Dubbed the S400 it combines a 279bhp V6 with a 20bhp electric engine, bringing total power to 299bhp with 277lb/ft of torque. It's expected the S400 will average about 27mpg, putting it slightly ahead of the Lexus LS600hL. The magazine goes on to speculate that the hybrid S-class will go on sale in mid-2009, shortly after a hybrid version of the ML SUV. [Via Autocar]