The Hummer H1 was available in three major variants: a convertible-like soft top, a four-door hard top Sport Utility Truck and an "Alpha Wagon" body version. Less known variants were a two-door pickup truck and a four-door slantback, which shares the same body style of the Humvee employed by the U.S. Military. The convertible/soft top and the station wagon versions were the last types available to individual consumers.
The Hummer H1 shares some common driveline parts with the HMMWV. These include brakes, axles, frame and major body panels (hood, tailgate and quarter panels) are shared between the HMMWV and Hummer H1. All H1s and HMMWVs were produced on the same assembly line; of which civilian H1s were then painted and finished in a separate building opposite the parking lot.
The H1 models are inherently stable due to their wide track. They can submerge 30 inches (76 cm) of water and climb a 22-inch (56 cm) step. Their stock ground clearance of 16 inches (41 cm) is made possible by tucking driveline components inside a channel in the central space between the left and right seats. They have high approach/departure angles of 72/37.5 degrees. Most H1s are equipped with a Central Tire Inflation System (CTIS), which enables the driver to increase or decrease the tire air pressure at the push of a button, since lower tire pressures are more suited for off-road, and higher tire pressures are desirable on-road.
The H1 features 16 inches (40 cm) of ground clearance as well as aggressive approach and departure angles, allowing it to clamber over a 22-inch (56 cm) high obstacle, handle a 60 percent grade and wade through up to 30 inches (76 cm) of water.
Hummer H1s have other unusual features, such as inboard brakes and portal gears that allow the drivetrain's half shafts a higher placement, for greater ground clearance. The radiator is up high, sloping over the engine on a forward-hinged hood. The air intake is high-mount, enabling the H1 to ford waist-level water. Rather than using simple runflat tires, magnesium-aluminum alloy or rubber inserts are an optional feature for runflat ability.