Mercedes-Benz M112 engine

Mercedes-Benz M112 engine
Overview
ManufacturerMercedes-Benz
Production1996–2015
Layout
Configuration90° V6
Displacement2.4 L (2,398 cc)
2.6 L (2,597 cc)
2.8 L (2,799 cc)
3.2 L (3,199 cc)
3.7 L (3,724 cc)
Cylinder bore83.2 mm (3.28 in)
89.9 mm (3.54 in)
97 mm (3.82 in)
Piston stroke68.2 mm (2.69 in)
73.5 mm (2.89 in)
84 mm (3.31 in)
Cylinder block materialAluminum
Cylinder head materialAluminum
ValvetrainSOHC 3 valves x cyl.
RPM range
Max. engine speed6,000-6,400 rpm
Combustion
SuperchargerIHI Twin-screw type (in some versions)
Fuel systemSequential fuel injection
Fuel typeGasoline
Cooling systemWater cooled
Output
Power output125–260 kW (170–354 PS; 168–349 bhp)
Torque output225–450 N⋅m (166–332 lb⋅ft)
Chronology
PredecessorMercedes-Benz M104 (inline-6)
SuccessorMercedes-Benz M272

The Mercedes-Benz M112 engine is a gasoline-fueled, 4-stroke, spark-ignition, internal-combustion automobile piston V6 engine family used in the 2000s. Introduced in 1996, it was the first gasoline V6 engine ever built by Mercedes. A short time later the related M113 V8 was introduced.

All are built in Bad Cannstatt, Germany, except the supercharged C 32 AMG and SLK 32 AMG, assembled in Affalterbach, Germany.

All M112 engines have silicon/aluminum (Alusil) engine blocks with a 90° vee angle. The aluminum SOHC cylinder heads have 3 valves per cylinder. All use sequential fuel injection with two spark plugs per cylinder. All have forged steel connecting rods, a one-piece cast camshaft, iron-coated aluminum pistons and a magnesium intake manifold. To deal with the vibration problems of a 90 degree V6, a balancer shaft was installed in the engine block between the cylinder banks. This essentially eliminated first and second order vibration problems (see engine balance). A dual-length Variable Length Intake Manifold is fitted to optimise engine flexibility.