The Mercedes Benz M137 engine was a SOHC 5.8 L 60° V12 engine, with three valves per cylinder. It was built to replace the somewhat bulkier and heavier, yet more powerful, DOHC, four valves per cylinder, naturally aspirated, 6.0L M120 V12 unit. The M137 was used briefly between 1998 and 2002 model years for the S-Class and CL-Class. In addition to being less bulky and lighter than the M120 engine, it also produced considerably less output, however, producing as it did 367 PS (270 kW) and 390 lbf·ft (529 N·m) of torque.
The M137 was replaced by the M275/M285/M158 engine.