The Hummer H1 a civilian version of the U.S. Army's runabout. It is built for General Motors by AM General and sold a various GM dealerships. Similar in appearance is the Hummer H2, but it is based on GM's heavy-duty pickup trucks. For 2004, the H1 receives a new interior, 10 more horsepower, and a standard in-dash 6-disc CD changer.

Two body styles are offered: a 4-dr wagon and a 4-dr "open top" with a soft cover for the roof and cargo area. Both seat four people in two front bucket seats and two rear bucket seats. The lone powertrain is a GM-built 6.5-liter turbodiesel V8 and a 4-speed automatic transmission. Minor revisions for 2004 give the engine 10 more horsepower and slightly better torque. The standard 4WD system can be used on dry pavement and offers a low range for off-road driving. Because the H1 is a Class 3 Truck, it does not have to meet all safety guidelines mandated for smaller vehicles (for instance, it has no airbags). Antilock brakes and a tire-pressure monitoring system are standard.

The redesigned interior features new materials and a new radio with integrated 6-disc CD changer. The lone option is an Off-Road Adventure Package that includes locking front and rear axles, a winch, and 2-piece alloy wheels. Off-road tires are available with that package.