GMC’s All Terrain X treatment has moved up to the Sierra HD and can be had with the automaker’s 6.0-liter gas-powered V-8 or the next-generation Duramax 6.6-liter V-8 turbodiesel that General Motors unveiled last month.
The 2017 GMC Sierra 2500 HD All Terrain X features similar treatment to the Canyon and Sierra 1500 All Terrain X models shown earlier this year. In addition to its blacked-out appearance (also available in Summit White paint), the Sierra HD All Terrain X is fitted with 18-inch wheels with Goodyear Duratrac tires, a front skidplate, side steps, bed-mounted sport bar, LED off-road lamps, and a spray-on bedliner. Also included is the Z71 package that features twin-tube Rancho shocks, Hill Descent Control, and an underbody shield.
The Sierra HD All Terrain X can be had with the 6.0-liter V-8 (360 hp and 380 lb-ft of torque) or the next-gen 6.6-liter V-8 turbodiesel rated at 445 and 910 lb-ft. Much of the engine is new with stronger components, a new electronically control turbo providing 28 psi of boost, an improved air intake system, and an oil cooler with increased capacity. GMC says the new engine is quieter and more refined than the last-gen Duramax, which churned out an already stout 397 hp and 765 lb-ft.
That said, in the ongoing truck power war, GM’s new Duramax overtakes Ram’s 6.7-liter Cummins V-8 turbodiesel currently rated at 385 hp and 900 lb-ft. Ford, however, still sits on top in the torque department with its 6.7-liter Power Stroke V-8 making 440 hp and 925 lb-ft.