To understate the case, the Hummer H2 is a unique vehicle. Not at all what you might expect, but offering much more in terms of comfort.

Introduced late last year, the menacing looking H2 is actually shorter than the Lincoln Navigator, Ford Expedition, and Cadillac Escalade. However, at 81.2 inches, it’s the widest full size SUV and among the tallest at 77.8 inches. However, inside, it’s more like the Escalade than the stark Humvee military vehicle it was patterned after.

The H2 is joint venture between General Motors (GM) and AM General, which builds the rugged Humvee that became famous during the first Gulf War. AM General later began building the slightly more civilized Hummer H1 — a civilian version with a sticker price well in excess of $100,000 — more than twice that of the H2.

The H2 is based on the Chevrolet Tahoe SUV and uses many standard GM truck components. It’s exceptionally comfortable, quiet, and easy to drive. Its long 122.8-inch wheelbase contributes to the smooth ride, which can be improved with optional rear air springs.

The H2 is sold through GM-franchised dealers and built in a new 630,000-square-foot AM General plant near South Bend, Ind. It has the ability to produce 40,000 units a year and is much different than the AM General plant right next door that turns out the Humvee and H1, because it’s configured in many ways like the new, high-efficiency GM plants. Plans call for the plant to also build a Hummer Sport Utility Truck (SUT) which is expected to debut in June of next year as a 2005 model.

I’ve had a number of opportunities to put the H2 through its paces and have come away more impressed each time.

The first was at a press introduction event that began in San Jose and ended up in Hollister Hills, California. There, we took the H2 up 30+ percent grades on narrow two lane tracks and back down steeper grades. While waiting for our caravan to get to the rendezvous area, I intentionally put one wheel on the level surface and the opposite in a four foot ditch, which put the H2 on a 45 degree angle and having to conquer some pretty rough terrain to get out. It walked right out without a whimper — except from my driving partner.

I also drove it at Mudfest 2002, the Northwest Automotive Press Association’s grueling annual two-day SUV competition. The H2 never broke a sweat over the muddy uphill grades or the steep down grade that ended in foot-deep water and immediately became a 45-degree uphill climb. The H2’s automatic full time four-wheel drive system walked it down the muddy slope and seamlessly delivered enough power for the muddy uphill run.

The standard dual mode full-time 4-wheel-drive system can be left in the high-range open setting for normal daily driving. But coupled with high ground clearance, rock-defying underbody construction, huge tires, and short overhangs this system is so versatile there isn’t anywhere the H2 can’t go off-road.

I’ve also driven it several other times as part of my regular weekly test vehicle rotation. In spite of its off-road prowess, unlike both the Humvee and H1, which are thoroughly unpleasant daily drivers, the H2 is more comfortable and maneuverable than some other SUVs and pickups.

Under the tilt-forward hood, the H2 boasts a 6.0-liter old-style pushrod V8 that puts 316 ponies to the pavement with massive torque. It’s married to a smooth, responsive 4-speed automatic transmission and does the 0 to 60 drill in 10.5 seconds — fairly quick for a 6,400-pound truck.

There are no official fuel economy figures because the H2’s weight puts it outside the purview of EPA fuel economy reporting. But trust me; it’s a gas hog. The 32-gallon fuel tank gives it a decent cruising range, but you might grit your teeth watching the pump during a fill-up. I got between 9 and 11 miles per gallon around town and in the low teens on the highway — even though the engine is loafing at less than 2,000 rpm at 70 mph.

Inside, the H2 is much quieter inside than you might expect considering its size, weight (6,400+ pounds), shape, and the LY315/70R17 all-terrain tires. The H2 seats four to five tall occupants in comfort with an optional single third-row seat. The interior generally has an upscale, but utilitarian appearance with no wood used. The front bucket seats are large and supportive. Instrumentation is easy to read and vaguely reminiscent of the Escalade. Sound and dual zone climate controls are large, as are the dashboard ventilation ducts. OnStar is standard.

The big front console has a deep storage bin and a very cool aircraft-throttle-style shift lever. The rear windows also roll all the way down. It’s easy to see how the H2 would be very comfortable on a cross-country trip, and I found it painless in congested I-5 traffic. Parking in tight areas can be problematic, and because of its height, so are most parking and residential garages.

Base priced at just over $48.000, there’s an adventure option package featuring such items as a brush guard and roof rack crossbars and includes the optional rear air springs.

Also available is a luxury option package offering heated leather seats, 6-disc in-dash, Bose CD changer, roof rack and tubular assist steps. In addition, there’s a $995 power-sliding sunroof. Our last test vehicle, trimmed out with the luxury package, sunroof and bright yellow paint, stickered at $52,870. Expensive, but when you compare the luxury and off-road capability to the Navigator, Mercedes M-Class, BMW X5, Land Rover or some of GM’s own upscale SUVs, it’s actually pretty competitive.

Whines: The third seat, located in the cargo area right alongside a large inside-mounted spare tire which partially blocks the driver’s rear vision, is hard to get in and out of due to the floor height. Frankly, I wouldn’t want to have to sit back there. There is zero cargo room with the third seat in place, although it can be removed. With the 60/40 split-folding second-row seat flipped down, there is an adequate cargo area, but the high load floor makes dealing with heavy objects a chore.

Bottom Line: GM knows how to design comfortable heavy duty trucks and AM General knows more than a few things about go-anywhere military vehicles. The H2 is an outstanding collaboration that looks to the casual observer exactly like the macho Humvee and H1. In my view, it’s simply one of best vehicles of any kind ever sold by General Motors.