HMMWV (Humvee) primarily utilizes heavy-duty V8 diesel engines designed for durability rather than speed. While originally powered by General Motors (GM) 6.2L engines, most modern variants use a 6.5L engine produced by General Engine Products (GEP) , a subsidiary of AM General Engine Evolution & Specifications

This engine was a non-turbocharged, indirect injection engine. Its strength was its simplicity. In a combat zone, a sophisticated electronic engine control unit (ECU) is a liability; an EMP or a stray bullet could disable a modern high-tech engine. The 6.2L was largely mechanical. It was robust, easy to fix in the field, and reliable if maintained correctly.

This is the definitive Humvee motor. AM General and Detroit Diesel added a Garrett turbocharger, intercooler, and stronger internal components.

A large, horizontal radiator stack located under the hood for protection. Humvee 4-CT - AM General