The H3 has an extremely upright windshield and side windows that more closely resemble those in a turret than a typical family wagon, as well as the very short front and rear overhangs and increased ground clearance that are vital for negotiating the sort of extreme off-pavement environments Hummers have to be able to survive.

One area in which the H3 differs from other Hummers is in the blistered fenders that cover its widely set wheels and large tires. The standard tires are 32 inches in diameter; special off-road tires developed for the H3 by Bridgestone are 33 inches tall.

Large round headlights are positioned on either side of an upright grille with seven vertical slots. Large fog lights positioned below the headlights underscore the vehicle's height. Its width is accentuated by amber signal lamps positioned outboard of the headlights, up above the front tires at the front of bulging front fenders.

Lending even more strength to the H3's face is a wide black bumper with a pair of bolted-in D rings, each of which can support the vehicle's full weight. A visible reminder that Hummers are at home away from pavement, the H3 has a skid plate, bright metallic underbody armor designed to protect its oil pan and other powertrain components from damage.

The hood has louvers that look like those on the H1 or H2 and a pair of air boxes at the base of the windshield supports. While the louvers are non-functional, one of the boxes draws air into the 3.7-liter five-cylinder engine.

Because of its military heritage as a Humvee, the wheels on the Hummer H1 had an integrated tire inflation system. The wheels on the H2 and H3 have a similar look, though they do not provide inflation on the go. However, the H3 does come with a standard tire-pressure monitoring system.

The rear view of the H3 is dominated by the full-size spare tire mounted on the back of the rear door. A hydraulic strut eases the opening and closing this tire-carrying door, which is hinged on the driver's side and thus can be loaded from curbside in parallel parking situations.

As at the front of the H3, a metallic skid plate protects the fuel tank and other underbody components at the rear of the vehicle's chassis.

The H3X looks more subtle than it sounds. The flash of its bright-chrome brush bar is offset by its body-color grille. Its flattened wheels look more like wheel covers. Aesthetically, we like the standard units, with their six double spokes plus ersatz tire inflator, better. Ditto the optional cab-top clearance lights, which strike us pretentious. A unique spare tire cover at the rear of H3X turns the Hummer-signature tire inflator into a stylized bar of bright trim.

Sport utility vehicles traditionally are built on pickup truck platforms, and the Hummer H3 chassis is based on the platform of the Chevrolet Colorado and GMC Canyon mid-size pickups. However, only 10 percent of the pickup trucks' components carry over into the H3, and the engine and transmissions account for most of that commonality. The other thing the H3 has in common with its pickup truck cousins is that it is built on the same assembly line in Shreveport, Louisiana.