Innovative technologies without parallel

The exemplary figures achieved by the new engine for output and torque characteristics, economy, exhaust emissions and smoothness are the result
of a whole raft of innovative technologies. These include a number of new developments, the likes of which cannot currently be found in any other standard-production passenger car diesel engine. The principal features of the new Mercedes diesel engine:

• Two-stage turbocharging ensures high power output and optimum torque delivery.
• Fourth-generation common-rail technology with a rail pressure that has been increased by 400 bar to 2000 bar, plus a new piezoelectric injector concept featuring direct injector needle control creates the ideal basis for more flexible injection timing, leading to smoother engine running, lower fuel consumption and reduced emissions.
• The maximum ignition pressure is 200 bar which also contributes to the high output.
• Both the oil-spray nozzles and the water pump are activated in accordance with requirements to save energy.
• The camshaft drive is positioned at the rear in order to enhance running refinement and satisfy the exacting pedestrian protection requirements.
• The engine block is made from cast iron, the cylinder head from aluminium.
• Two water jackets guarantee maximum cooling even at the points of greatest thermal radiation; it is this that enables a ignition pressure of 200 bar and such a high power-to-displacement ratio.
• The aluminium pistons slide up and down in cast-iron barrels for minimum frictional resistance.
• The connecting rods are made from forged steel, and their weight has been optimised by the Mercedes engineers.
• In the interests of vibrational comfort, the forged crankshaft with its eight counterweights turns supported by five bearings. The radii of the crankpins are rolled for high strength.
• To compensate for the free vibration moments which are inherent to four-cylinder inline engines there are two Lanchester balancer shafts at the bottom of the engine block running in low-friction roller bearings rather than conventional plain bearings.
• A two-mass flywheel, featuring a primary flywheel mass fixed to the crankshaft that is connected to the secondary flywheel mass on the transmission by means of springs (technical term: spring-mass system), isolates the crankshaft's vibration stimuli from the drivetrain, thereby contributing to the engine's excellent smoothness.