One of the determining factors for maximum power output and for fuel consumption at full throttle, from an emissions point of view, is the maximum ignition pressure. With a pressure of 200 bar, the new four-cylinder diesel from Mercedes-Benz is one of the top-ranking passenger car diesel engines in this regard. To guarantee spontaneous starting, the engine is fitted with ceramic glow plugs which attain a temperature approximately 200 degrees Celsius higher than metallic glow plugs (1250��C as opposed to 1050��C) and are virtually wear-free. Mercedes-Benz put these glow plugs into series production for the first time in the predecessor diesel engine.

Two-stage turbocharging for high torque at all engine speeds

The new diesel unit draws the air it needs to breathe from not one but two turbochargers, marking the first ever instance of two-stage turbocharging in a series-manufactured passenger car diesel engine from Mercedes-Benz. The aim of this concept is to eliminate the inherent drawbacks of a single-stage turbocharger. These include, for instance, the moment of inertia of a large turbocharger, which drivers may perceive as sluggish start-off characteristics (turbo lag). What��s more, it is virtually impossible to reconcile good start-off abilities and maximum power along with low fuel consumption even at full throttle when deploying just a single-stage turbocharger.