Mercedes-Benz developing two new engines

The first new engine is a naturally-aspirated 3.5-litre V6 unit, which features a narrower angle block than Mercedes' current V6, at 60 degrees compared to 90 degrees. The new engine will feature a third-generation direct injection system with piezo-electric injectors, a more efficient combustion formula, multi-spark ignition and low-friction ancillaries, as well as a start-stop system that is said to improve fuel economy by up to 24 percent.

The new V6 engine is able to produce 301bhp, up from 268bhp previously, and 368Nm of torque, an increase from 350Nm from the previous unit. The new 3.5-litre V6 is expected to be fitted to the S350 and CL350 models later this year.

The other new engine is a 4.6-litre V8 with twin-turbocharging that replaces the existing 5.4-litre V8 unit. The new engine produces 429bhp and 700Nm of torque, and will debut in the CL500 later this year. Equipped with start-stop technology, the new powerplant improves fuel economy by 22 percent.