After adding two line-topping S Class models - the S600 and S65 AMG - Mercedes-Benz has announced two additional engines have been added to the already burgeoning family. Currently earmarked only for Europe, the BlueTEC Hybrid differs from the S500 Plug-In Hybrid; its electric engine only serving to assist the 2.2-liter diesel engine during acceleration and for breaking energy recovery. According to European testing, the car will provide a combined cycle of 54mpg.

The other new model, the S350 BlueTEC 4Matic, will boast a turbo-diesel 3.0-liter V-6, mated to Benz's 4Matic all-wheel-drive. With 258 horsepower and 457 lb-ft of torque, it's rated at 40 mpg in European testing, reaching top speeds of 155 mph. Both of these new environmentally-friendly flagships will come in short and long wheelbase versions. While neither model has been confirmed for the US as of yet, they will both hit European dealerships this coming March. Expect at least the S350 BlueTEC to make its American debut later this year as a 2015 model.