A Hummer is hard too miss -- that bold face and toothy seven-slot grille, a flat roof and square cabin with narrow windows looking like a military bunker. The original H1 Hummer, a civilized version of the military High Mobility Multipurpose Wheeled Vehicle, or Hum-Vee, comes from Hummer's parent company, AM General. But General Motors has marketing rights to the Hummer label and at GM's Hummer Division there are junior versions spawned from the H1. Hummer's 2006 line encompasses the H1 Alpha with boosted power, the H2 SUV and H2 SUT (sport-utility truck), plus a new reduced-size SUV tagged as the H3.

This model traces to the original civilian version of the military Hum-Vee, and it has awesome off-road capability. Conformed as a boxy four-door SUV, the H1 Alpha scores significant enhance-ments for powertrain and cabin appointments. It gets GM's Duramax 6600 6.6-liter V8 direct-injection turbo-diesel engine, which delivers huge power and torque ratings -- 300 hp and up to 520 lb-ft of torque. The Duramax V8 ties to an Allison 1000 five-speed automatic transmission with Tow/Haul mode. To accommodate the new engine, H1's body rises higher by two inches, and disc brakes are bigger to improve stopping power.

Heavy-duty four-wheel-drive (4WD) equipment goes into every H1 with sophisticated controls to automatically reduce tire spin on slippery terrain by braking a spinning wheel. In the four-seat cabin, H1 Alpha stocks luxury goods with comfortable bucket seats, fine leather upholstery and an updated and revised dash design.

The H2 SUV seems like a smaller version of the H1. It rides on a modified version of the chassis of GM's Chevrolet Tahoe and GMC Yukon wagons, with mechanical components including a 325-hp 6.0-liter V8. A broad track and extended wheelbase with brief overhangs and super-sized tires work to make H2 exceptionally stable, and a high ground clearance with underbody skid-plate shielding ensures it can navigate rough off-road terrain.

Every H2 has a Borg-Warner two-speed electronically controlled full-time 4WD system. The cabin has bolstered buckets and optional leather upholstery with high-tech audio and navigation gear. For 2006 a special edition appears in Pacific Blue body paint with 17-inch polished aluminum wheels and a roof-mounted light bar plus cabin trim in carbon fiber. Fresh options range from a reverse-view camera with two-inch dashboard screen to a backseat DVD equipment with twin video screens mounted behind front headrests.

This version of H2 functions as both wagon and truck, which explains the SUT tag. Where the SUV shows an extended roofline and boxed rear wagon bay, however, the SUT differs by lopping off the roof to form an abbreviated truck bed roughly four by three feet in size. Then the back wall of the cabin functions as a door -- it folds down and forms a generous extension of the truck box. With the back wall folded down, the cargo bay extends for six feet to the tailgate. With the wall raised and window up, the cabin is sealed off from the truck bed. A conventional cabin holds two buckets up front and a three-person bench in back. Add-on equipment for the SUT extends from a roof light bar and dashboard DVD navigation system to XM satellite radio service.

Latest vehicle to wear the Hummer badge looks like a whittled and honed H2 SUV. Dubbed the H3, it's a mid-size model that's easy to maneuver on a parking lot and marked by attractive price points. H3 rises from GM's global compact truck platform which also supports Chevrolet's Colorado and GMC Canyon pickups. It's stiff in H-shaped design with cross bracing and underbody skid plates added below the engine, transfer case and fuel tank.

Strength for H3 stems from GM's 3.5-liter in-line five-cylinder plant that climbs to 220 hp with 225 lb-ft of torque through a five-speed manual transmission or Hydra-Matic 4L60-E four-speed automatic. The electronically controlled 4WD system has a two-speed transfer case with locking differentials center and rear. For safety, StabiliTrak skid controls, OnStar telecommunications and curtain-style air bags are standard issue on H3. Optional tires include 32-inch all-terrain Goodyears or 33-inch off-road Bridgestones.