The OM615 engine family was a straight-4

Straight-4

The inline-four engine or straight-four engine is an internal combustion engine with all four cylinders mounted in a straight line, or plane along the crankcase. The single bank of cylinders may be oriented in either a vertical or an inclined plane with all the pistons driving a common crankshaft....

 Diesel

Diesel engine

A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

 automobile engine from Mercedes-Benz

Mercedes-Benz

Mercedes-Benz is a German manufacturer of automobiles, buses, coaches, and trucks. Mercedes-Benz is a division of its parent company, Daimler AG...

 used in the 1970s and 1980s.

OM615.940

The OM615.940 was a 2.0 L (1988 cc) engine with an 87 mm bore and 83.6 mm stroke. Power output was 55 hp (41 kW) through 1979 and rose to 60 hp (45 kW).

Applications:

• 1976-1979 200D
  Mercedes-Benz W123
  W123 is the internal chassis-designation Mercedes-Benz used for their executive line of cars, manufactured between 1976 and 1985.The W123 models surpassed their predecessor, the W114 and W115 models, as the most successful Mercedes, selling 2.7 million cars before replacement by the W124 after 1985...
  
  , 55 hp (41 kW)
• 1979-1985 200D
  Mercedes-Benz W123
  W123 is the internal chassis-designation Mercedes-Benz used for their executive line of cars, manufactured between 1976 and 1985.The W123 models surpassed their predecessor, the W114 and W115 models, as the most successful Mercedes, selling 2.7 million cars before replacement by the W124 after 1985...
  
  , 60 hp (45 kW)

OM615.941

The OM615.941 was a 2.2 L (2197 cc) version with the same 87 mm bore but a longer 92.4 mm stroke. Power output was 59 hp (45 kW) and 93ft lb of torque.

Applications:

• 1976-1979 220D
  Mercedes-Benz W123
  W123 is the internal chassis-designation Mercedes-Benz used for their executive line of cars, manufactured between 1976 and 1985.The W123 models surpassed their predecessor, the W114 and W115 models, as the most successful Mercedes, selling 2.7 million cars before replacement by the W124 after 1985...