6-cylinder OM 656

6-cylinder OM 656 in-line engine is the strongest diesel engine mounted in Mercedes passenger cars in history. The engine has, among others, two-stage turbocharging system and Camtronic variable valve timing system, which was used for the first time. In its design, an aluminium block was combined with steel pistons and improved “Nanoslide” cylinder coating. In comparison to its predecessor, the engine’s power increased to over 313 hp (230 kW) against the original 258 hp (190 kW), while fuel consumption dropped by 7%.

OM 656 was designed with new emission standards in mind: reducing fuel consumption and obtaining low exhaust emission. Elements of the system responsible for effective exhaust gas treatment were installed directly next to the engine – as a result it loses less heat and has better working conditions. The effect is enhanced by Camtronic switchable camshaft, which helps with heating of the exhaust system without affecting fuel consumption.