Unlike its predecessors, the Hummer H1 Alpha no longer uses the 6.5-liter Optimizer turbo-diesel V8 that put out 205 horsepower and 440 lb.-ft. of torque. Instead, GM's 6.6-liter Duramax turbo-diesel V8 delivers a 46-percent increase in horsepower, up to an impressive 300 hp at 3,000 rpm and a 70 lb.-ft. bump in torque to an impressive 520 lb.-ft. at just 1,500-1,600 rpm. Additionally, the previous-generation four-speed automatic transmission has been shelved in favor of a five-speed Allison 1000 unit.

General Motors eagerly brandishes these power figures to prove the on-road capability of its most extreme off-road vehicle. Engineers even claim an improved 0-60 acceleration time of 13.5 seconds, a full three seconds faster than the old H1. But, these days, news likely to please converts and, perhaps, the unconverted, is the "significant improvement" in fuel economy. Hummer executives report that the H1 Alpha will achieve mileage of up to 12 mpg, and estimate that the 2006 H1 Alpha’s 51.5-gallon fuel tank will allow for a 570-600 mile range between fill-ups.

But, those who make the decision to own a Hummer aren't truly concerned with fuel economy, and GM knows it. Consequently, the focus is on exclusivity, image, and off-road prowess –attributes that attract Hummer’s entrepreneurial clientele. In exchange for about $150,000 (our as-tested price), GM executives believe the pricey H1 Alpha offers consumers a unique machine that redefines the limits of personal mobility.

Regarding image, the aftermarket bling attached to high-end 4WD models, like the Hummer, now comes straight from the factory. A skid plate cover, front and upper grille covers, door handles and bezels, and a rear bumper cover, all finished in stainless steel, are available. Chrome trim decorates the tubular side steps, front bumper cover, headlight bezels, hood corner trim, hood latches, tailgate hinge covers, and the air intake cap. Additionally, 'Alpha' and 'Duramax' badges are found just above the rear bumper and on the front driver's side body corner, respectively. The body, with its Gulf Storm and Shock-and-Awe imprint, is made of hardened 6061 T6 aircraft aluminum and the panels are firmly secured with adhesive and rivets. For 2006, Hummer has also redesigned the H1's wheels.