With 520 lb-ft of torque on tap, the old CV axles were set aside for beefier pieces, which now attach to the newly enlarged inboard 12-inch brake rotors for better stopping power. A whole new cooling stack also had to be developed, this time incorporating an intercooler and fuel cooler-a change that required the mechanical fan to be run off the crank pulley and angled up to the radiators through a small gearbox.
While the engineers were evaluating the H1 chassis for areas of improvements, they decided to take some liberties in refinement. One of these areas was the geared hub assemblies, which now feature helical-cut gears instead of the straight-cut gears of previous H1s. This not only lowers noise, but also reduces the rocking sensation upon stopping, a characteristic common to older H1s.
The addition of the Duramax and all of its improvements to the H1 chassis make the H1 Alpha a better real-world machine. The Hummer H1 Alpha's crawl ratio has improved by 25 percent to 41.5:1. Acceleration from 0 to 60 dropped by 18 percent, to 13.5 seconds. And the towing capacity improved 13 percent to as much as 9,303 pounds on an open-top model.
Hopping into the Hummer reminds you instantly of its functional roots as a purpose-built machine. Each seating position only has a small cockpit space, as the driver and occupants are draped around the engine and transmission. Sightlines out the front of the H1 are generally good, but there are unavoidable blind spots to the rear. Still, the driving experience is unlike any other truck on the planet, and should you ever find yourself in one, prepare yourself for the inevitable giving of rides to all the neighbor kids, the convoy of National Guardsmen who will wave you in to their ranks on the highway, and the barrage of thumbs-up you are sure to encounter. And you thought you felt like a rock star in the H2!
On the highway, the H1's full-time 4WD system with four-channel ABS do a great job of making the Hummer easy to drive, as long as you remember how wide you are. The Duramax accelerates with authority, and the four-wheel independent suspension offers a pretty smooth ride. Using the impressive Monsoon sound system to drown out the moderate wind and tire noise, the Hummer can cruise effortlessly at 80 mph all day long without beating up or tiring the driver.
Even though the Hummer is more refined on the highway, the H1 Alpha's main mission objective is to tackle the toughest terrain and bring its occupants home safely and reliably. Despite the refinements, the H1 Alpha is as capable as ever and can still climb a 22-inch vertical wall, cross a 60-percent grade, traverse a 40-percent side slope with 2500 pounds of payload, and ford 30 inches of water. With the Central Tire Inflation System (CTIS), you can air up or down on the fly, and if you happen to get a flat, the run-flat bead-lock system will get you safely off of the trail. Front and rear Eaton E-Lockers are even offered as a factory option.
Until you have experienced it first-hand, it is hard to explain just how right one of these iconic machines looks while sailing across a mountainous plain. They exude so much character, and are capable far beyond any level most civilians will ever experience. If you have that spirit of adventure calling, and you are one of the lucky 500 or so a year to buy one, it won't take you long to realize what makes the H1 so genuine and why we consider it one of the best factory-built wheelers of all time.
Vehicle model: '06 Hummer H1 Alpha 4-Door Wagon
Base Price: $140,796
EngineType: Duramax 6600 V-8
Displacement (liter/ci): 6.6/403
Bore x stroke (in.): 4.055 x 3.897
Compression ratio: 17:1
Aspiration: EFI, turbocharged, air-to-air intercooling
Mfg.'s hp @ rpm: 300 @ 3,000
Mfg.'s torque (lb-ft) @ rpm: 520 @ 1,600