Mercedes-Benz OM 656.

Most powerful diesel car in Mercedes-Benz history

OM 656.

The new six-cylinder in-line diesel engine OM 656 is a milestone of Mercedes-Benz driving technologies and an important contribution to achieving the global climate goals.

The new engine comes with the new S-Class – in two output classes: The Mercedes-Benz S 350 d has an output of 210 kW (286 hp) and 600 Nm (combined fuel consumption: 5.1 l/100 km; combined CO₂ emissions: 134 g/km). The Mercedes-Benz S 400 d with 250 kW (340 hp) and 700 Nm is the most powerful series production car diesel engine ever offered by Mercedes-Benz (combined fuel consumption: 5.2 l/100 km; combined CO₂ emissions: 135 g/km). Both variants are also available with 4MATIC all-wheel drive.

More power, less consumption and emissions

Although the output has increased noticeably compared to the preceding model, the new engine consumes up to six percent less fuel. The special traits of the top-of-the-line engine in the diesel family include the stepped-bowl combustion process, two-stage turbocharging and, for the first time, the use of CAMTRONIC variable valve-lift control. Its design features a combination of aluminium engine block and steel pistons as well as further improved NANOSLIDE® coating of the cylinder walls.

The new six-cylinder diesel engine is designed to comply with future emissions legislation (RDE – Real Driving Emissions). All the components of relevance for efficient emissions reduction are installed directly on the engine. The integrated technology approach combining the new stepped-bowl combustion process, dynamic multi-way exhaust-gas recirculation and near-engine exhaust-gas aftertreatment, for the first time combined with variable valve-lift control, makes further reduced consumption with low emissions possible. Thanks to the near-engine insulated configuration, exhaust-gas aftertreatment has low heat loss and extremely favourable operating conditions.