Hummer H1 / HMMWV

In 1979, the U.S. Army issued a request for a new vehicle design capable of meeting demanding military standards, including the ability to modify a single base platform for different mission profiles. Chrysler Defense, Teledyne Continental, and AM General each submitted proposals. After extensive testing and revisions, the Army awarded AM General a $1.2 billion contract to produce the High Mobility Multi-purpose Wheeled Vehicle, better known as the HMMWV or Humvee.

The Humvee quickly became an integral part of the military's vehicle fleet, serving not only the Army but also the Marines, Navy, and Air Force across a wide range of operations. Its reputation for go-anywhere toughness caught the attention of civilians, and in 1992, AM General began offering a civilian version marketed as the Hummer. In 1999, GM purchased the rights to produce vehicles under the Hummer name, creating two parallel lines: AM General's military vehicles and GM's consumer-oriented Hummers.

The civilian Hummer shared its chassis with the military version, and AM General even used the same manufacturing facilities to build both. From 1992 to 1995, the Hummer used a diesel engine, either a 6.2-liter or 6.5-liter depending on the year. From 1995 to 1997, AM General experimented with a 5.7-liter gasoline V8, but the Hummer's substantial curb weight of roughly 7,000 pounds proved too much for the gas engine, and AM General returned to diesel power after 1997.

The Hummer's brake traction control system gives it the ability to redistribute torque even when a wheel is completely off the ground, making it a dream for serious off-road enthusiasts. Safety ratings were exceptional, which you would expect from a vehicle originally designed for combat missions. Whether used as a military workhorse or a civilian trail machine, the Hummer demands a cooling system that can handle extreme conditions. Griffin Thermal Products builds exact-fit aluminum radiators for civilian and military Hummers, delivering the cooling performance these unstoppable vehicles deserve.