Hummer

Manufacturer        AM General
Production            1992–2006
Model years         1992–2004, 2006
Assembly             Mishawaka, Indiana, United States

Class                    Large truck/SUV
Body style             4-door pickup truck
                             2-door pickup truck
                             4-door wagon
                             4-door convertible - based on High Mobility Multipurpose Wheeled Vehicle

Layout                 Front engine, four-wheel drive
Engine                6.2 L Detroit Diesel V8
                           6.5 L Detroit Diesel V8
                           5.7 L Vortec V8
                           6.5 L turbo Detroit Diesel V8
                           6.6 L turbo DMAX Diesel V8

Transmission      GM TH400/3L80 3-speed automatic
                           GM 4L80-E 4-speed automatic
                           Allison 1000 5-speed automatic
                           Allison 1000 6-speed automatic

Wheelbase       130 in (3302 mm)
Length              184.5 in (4686 mm)
Width                86.5 in (2197 mm)
Height               77 in (1956 mm)
                         2004–06: 79 in (2007 mm)
                         Pre-2003 Wagon: 75 in (1905 mm)
Related            High Mobility Multipurpose Wheeled Vehicle (an AM General military vehicle)

The Hummer H1 is a civilian off-road vehicle based on the M998 High Mobility Multipurpose Wheeled Vehicle (or Humvee), which was created by AM General. The vehicle was produced from 1992 through 2006, and was the first of what became the Hummer line. It was initially known only as the "Hummer"; however, in 1999 in a joint venture between General Motors and AM General, GM began marketing the Hummer H2, which was built on the Chevrolet Tahoe chassis. It was at this point that the original Hummer was given the H1 designation. For collectors, the most desirable model is the H1 Alpha, produced in the final model year of 2006. It had the most powerful engine and the best fuel mileage of the H1 vehicles. Overall, the H1 was a very limited production vehicle.

The basic Hummer vehicle is 6 feet tall, 7 feet wide, 15 feet long and weighs 5,200 pounds (2,340 kilograms). AM General used a steel frame with five cross members to support the weight of a vehicle with a payload of up to 2,500 pounds (1,125 kilograms), allowing a gross vehicle weight (GVW) the weight of the vehicle, passengers and maximum payload of 7,700 pounds (3,465 kilograms). In order to keep the vehicle's total weight at a manageable level, AM General used aluminium to construct the body of the car. The aluminium is strong enough to support heavy armaments or carry troops, yet is able to flex when the Hummer travels over rough ground.

A double A-arm independent suspension in the front and rear with hydraulic shock absorbers allow the Hummer to tackle unforgiving terrain. It also has torque-biasing differentials and four-wheel disc brakes, which give the Hummer the ability to continue moving even when some of the wheels lose contact with the ground.

The Hummer is a fully four-wheel drive vehicle the engine powers all four wheels at all times. It also has open-differential gears with Torsen differentials. When one wheel begins to slip, it loses torque. The Torsen differential system senses the loss of torque and increases torque to the other wheels. Coupled with the brake traction control system, the Humvee's Torsen differentials give the vehicle incredible off-road capabilities.

Hummers have a 25-gallon (95-liter) fuel tank and can go about 300 miles (480 kilometers) before needing to refuel -- meaning a basic Hummer gets about 12 miles to the gallon, though heavier Hummer variations are somewhat less efficient. As per the Army's request, all military Hummers run on diesel fuel and have an automatic transmission the Army wanted all its vehicles to run on the same fuel system and felt that automatic transmissions would be easier for new trainees to learn quickly.

The Hummer has power steering and includes a 12/24-volt electrical  system. Either two or four soldiers can sit inside the cab of the vehicle, depending on the variant. According to AM General, the location of the seats on either side of the drive train helps give the Hummer a low center of gravity.

The vehicles have powerful combat locks on each of the doors to help keep soldiers safe. Unfortunately, some soldiers have found it impossible to open the doors if the locks are damaged out in the field. To fix this problem, AM General now includes a D-ring on all Hummer doors. The D-ring is a loop of metal attached to the outside of the Hummer's doors and functions as a place to attach a cable or chain. A winch or similar device can pull the cable, forcing the door open and letting soldiers out of the vehicle.

That's the lowdown on the basic Hummer. Using this as a starting platform, AM General produced 15 different HMMWV variants. They designed 44 interchangeable Hummer parts, allowing the Army to modify, maintain and repair vehicles with incredible efficiency, economy and flexibility.