The Mercedes-Benz S400 Hybrid was a variant of the W221 S-Class that debuted for the 2010 model year. The S 400 Hybrid was the first S-Class variant to feature a hybrid powerplant, with a 3.5L V6 engine paired to a 3 phase AC magneto electric motor. The combined output of the hybrid powerplant was 295hp, which was sent to the rear wheels via a 7 speed automatic transmission. Production of the W221 S400 Hybrid ended in 2013, but the model series continued life in the next generation W222 Mercedes-Benz S-Class as the W222 S400 h