For the V6, the main changes are a new narrow-angle block, while the V8's capacity is reduced, doubled by the introduction of twin-turbo induction. Both engines will also get third-generation direct injection with piezo-electric injectors, revised combustion, multi-spark ignition and low-friction ancillaries. All these new solutions are expected to improve fuel efficiency by up to 24 percent.
The V8 engine will have a capacity of 4.6 liters, down 15 percent from the 5.4 liters of its predecessor. Peak power will increase to 435 horsepower (up from 388 hp), while torque will be 32 percent higher, at 516 lb-ft (700 Nm). “The driver experiences the same pleasant and effortless performance from the new V8 as that delivered by a mighty, naturally aspirated 7.0-litre engine,” says Mercedes, quoted by Autocar.
The new V8 will debut in the CL500 this autumn and will have a fuel economy of 29.7 mpg, with the CO2 dropping to 224 g/km. The new 3.5-liter V6 engine will feature stop-start technology, which cuts consumption in traffic, for the first time on a multi-cylinder Mercedes-Benz engine. Power rises to 305 horsepower, up from 272 hp, while torque increases to 272 lb-ft. (368 Nm).
The new V6 will feature in the S350 from the autumn onwards and the CL350 starting the winter, with major improvements to fuel economy and CO2 output. In the S350, the new V6 is claimed to be capable of 37.1mpg - a 24 per cent improvement - and 177g/km.
“These figures make the new V6 the benchmark in its segment for a comparable output,” says Mercedes.