Mercedes-Benz has released a new generation of V-engines, and revisions start from the basic construction with the use of lightweight aluminium crankcases, pistons and cylinder heads while the crankshaft, connecting rods and valves are now of special forged steel.
Other improvements to the V8 and V6 include multi-spark ignition and a third generation direct fuel injection system with spray-guided combustion and piezo-electric injectors that increase fuel efficiency. This creates a homogeneous combustion in the V8 and stratified combustion in the V6 for a leaner burn. Add in start stop technology, shift point adjustment, specific friction reducing measures and overall fuel consumption is reduced by more than 20%.
The new V8 (non AMG, to power ‘500’ badged Mercs) comes with two turbochargers for 700 Nm of torque at 1,800 rpm. Although the 4,663 cc unit sees a 15% decrease in engine displacement, it produces 12% more power than before – 435 bhp versus 388 bhp – and that headline grabbing 700 Nm is 32% more than the previous 530 Nm. Stuttgart says that the power available at low revs is similar to that of a naturally aspirated 7.0-litre engine.
Fuel consumption has seen a drop too. The CL500 previously did 12.3 litres per 100 km; with the new engine the big coupe manages 9.3 litres for every 100km, which is significant. CO2 figures are down to 224 g/km from 288 g/km.
The most notable change to the naturally aspirated V6 is the shifting of the V angle between the cylinder banks from 90 degrees to 60 degrees. Mercedes has future proofed this unit by designing it to accommodate future turbocharging applications with the help of a modular design concept. This in turn allows the balancer shaft to counter primary vibrations for better smoothness.
While the 3.5-litre size is unchanged, the V6 gets a new intake and exhaust gas system with a variable-resonance intake manifold and optimised airflow. These combine for increased power (from 272 bhp to 306 bhp) and torque (from 350 Nm to 370 Nm). With it, the S350 achieves 7.6 litres per 100 kilometres and 177 g/km of CO2, a big improvement from the engine it replaces.
Look after the jump for more images of the engine.
[zenphotopress number=999 album=1116]