Nuts and Bolts Though it’s underpowered, the 2006 Hummer H3 bests its closest competitors, and even the Land Rover LR3, when it comes to clearances for difficult off-roading.

Built on GM’s compact pickup truck platform that serves as the basis for the Chevrolet Colorado and GMC Canyon, and equipped with an inline five-cylinder engine beneath its aggressive snout, the 2006 Hummer H3 could clearly benefit from more power to move its nearly 2.5 tons of mass. But then again, a 20-mpg fuel economy estimate will be a strong selling point, if you need to soapbox the environmentalists.

Though equipped with variable valve timing, dual overhead cams, electronic throttle control, and counter-rotating balance shafts, the 2006 Hummer H3’s 3.5-liter inline five-cylinder engine delivers just 220 horses and 225 lb.-ft. of torque. On a positive note the engine produces minimal noise, vibration and harshness, for a quieter ride than you might expect from a Hummer. Either a five-speed manual or a four-speed automatic transmission shuttle power to all four wheels, and the automatic has been engineered with shift modes that are designed to enhance low-range operation.

All H3s arrive with a two-speed 4WD transfer case by Borg-Warner. The standard low range ratio is 2.64:1, but 4.03:1 gearing is available as part of the Adventure Package for more intense obstacle clearing. The H3s compact proportions – a 111.9-inch wheelbase inside a 186.7-inch body – contribute to excellent maneuverability thanks to a 37-foot turning circle, an approach angle of 40 degrees, a departure angle of 37 degrees, and a breakover angle of 25 degrees (when equipped with the 33-inch Bridgestones). Additionally, a ground clearance of 9.1 inches allows the H3 to ford 16 inches of water at 20 mph or 24 inches at 5 mph. Vertical barriers up to 16 inches are also conquerable. Four-wheel-disc brakes with ABS and Dynamic Rear Proportioning feature 12.4-inch front rotors and 12.3-inch rear discs. Power-assisted rack-and-pinion steering directs standard P265/75R16 Goodyear tires on 16-inch aluminum wheels bolted to an independent front suspension and a solid rear axle. The optional Bridgestones are specified as LT285/75R16C.

The H3’s ground clearance and sheet metal design make it more versatile off-road than the Jeep Grand Cherokee (ground clearance: 8 inches; approach angle: 34.1 degrees; departure angle: 27.1 degrees; breakover angle: 20.6 degrees); the Nissan Xterra (ground clearance: 9.5 inches; approach angle: 33.2 degrees; departure angle: 29.4 degrees; breakover angle: 24.6 degrees); and the Toyota 4Runner (ground clearance: 9.1 inches; approach angle: 31 degrees; departure angle: 24 degrees; breakover angle: not available). On extreme terrain, even the much more pricey Land Rover LR3 (ground clearance: 9.5 inches; approach angle: 37.2 degrees; departure angle: 29.6 degrees; breakover angle: 27.9 degrees) can’t clear boulders as capably as the 2006 Hummer H3.