The Mercedes-Benz S-Class will receive a new twin-turbo petrol V8 next year as part of a roll-out of high-tech new engines by the German manufacturer. The new VS, codenamed M176 and developed by AMG, is one of four new powerplants. It will be introduced in the S-Class in mid-2017 in a derivative named S560, a revival of a badge not used for decades. Mercedes says the new V8 makes more than 470bhp, up from the449bhp of the M278 V8 it replaces, and 516lb ft.
The engine uses at least 10% less fuel thanks to its smaller displacement, down from 4663ccto 3982cc, and a cylinder deactivation system that shuts off four cylinders under partial throttle loads. Technology from the V8 engines already used by the Mercedes-AMGGT and C63 has been incorporated into the M176, such as turbochargers mounted between the cylinder banks – a so-called ‘hot inner V’ arrangement, which has resulted in a power gain of 5% over the M278. The S-Class is also set to receive a new six-cylinder inline petrol engine, codenamed M256, which is the first engine Mercedes has designed for electrification from the outset.
It features a 48V electrical system that runs ancillary items such as the water pump and air-con compressor, which otherwise consume power and reduce economy in a conventional engine, along with a new integrated starter-alternator (ISG) and electric auxiliary compressor (eZV), which combine to produce a power boost that negates turbo lag.
Peak power and torque are approximately 402bhp and 369lb ft, compared with the 328bhp and 354lb ft of the outgoing M276 V6. Emissions of CO2 have been reduced by around 15% and, as with the new V8, a petrol particulate filter will be used to trap soot. Mercedes believes the less fashionable in-line six-cylinder layout offers packaging advantages when combined with the 48V electrics and ISG.
The absence of a belt drive makes the engine shorter, and there’s space for ancillary components either side of the cylinders. Another new engine is an in-line six-cylinder diesel, codenamed 0M656, which is the most powerful passenger car diesel engine yet built by the company. Power is 308bhp, compared with the 254bhp of the outgoing V6 diesel, but the engine uses 7% less fuel.
The fourth new engine is the 2.0-litre four-cylinder petrol M264, with twin-scroll turbochargers. Mercedes claims it has a specific output of around 134bhp. The M264 unit has a belt-driven 48V starter-alternator (BSA) that is responsible for fuel-saving hybrid functions, such as energy recuperation and providing a power boost to the engine at low revs. The units, which are part of a £2.7 million investment, have been developed at the firm’s new Powertrain Integration Centre in Sindelfingen.