Originally developed as a general-purpose vehicle for the United States military during the 1970s, the four-wheel drive previously known as the HMMWV (High Mobility Wheeled Vehicle) or Humvee was adapted for civilian use in 1992. Simply called the Hummer, the vehicle quickly became an unconventional and extravagant luxury machine. Hummers were built by AM General on the same assembly line as the military models.
In 1999, General Motors assumed the role of marketing the Hummer brand for the civilian market. General Motors converted the Hummer into a brand and rebranded the original, military-designed model as the H1 in 2002. Offered as a four-door open top as well as an enclosed wagon body style, the 2002 Hummer H1 was powered by a GM diesel 6.5-liter V-8 engine. Producing up to 430 pound-feet of torque, the turbocharged diesel powerplant was paired with a heavy-duty four-speed automatic transmission and an aggressive four-wheel drive system. Popular equipment on the Hummer H1 was a Central Tire Inflation System that can alter air pressure in the vehicles tires through control in the cabin.
Designed to seat four passengers, the interior of the Hummer H1 included air conditioning, cruise control and power windows. In 2006, The Hummer H1 was offered as a heavily modified Alpha model. The Hummer H1 Alpha model received up to 520 pound-feet of torque from a 6.6-liter Duramax turbo diesel engine. The higher performance 2006 Hummer H1 was constructed on an upgraded high-strength steel frame. Due to rising oil prices, stricter emissions and decreased consumer demand, the Hummer H1 was no longer available for the civilian market following the 2006 model year.