The 2017 GMC Sierra HD All-Terrain X is finally here. This is the top off-road package for GMC heavy duty truck lineup. The All-Terrain X package is only available on the 2500-series (aka. 3/4 ton) crew cab Sierras. It uses the Z71 off-road package as the basis. The truck has off-road tuned suspension with Rancho shocks. The blacked-out wheels, the Goodyear Wrangler Duratrac tires, the black grille surround, sidesteps, and the sports/light bar behind the cab add to the truck’s mean attitude. The bed-mounted sports bar is the easiest way to identify the All-Terrain X among all other Sierra HD 4×4 or All-Terrain trucks.
The All-Terrain X can be had with two engine options: the 6.0L gasoline V8 or the new 6.6L Duramax diesel V8 that you see here. You know it’s the 2017 diesel because of the hood scoop in the hood. The new “L5P” Duramax produces 445 horsepower and 910 lb-ft of torque. It’s still backed up by a 6-speed Allison automatic transmission.
On the inside, there are extra-cushy leather seats with special inserts and the “all-terrain” logo in the gauge cluster.
The All-Terrain X has the hardware to backup its off-road credentials. The suspension soaks up rough off-road trails. The big Duramax V8 has more than enough torque to climb steep hills (nearly 20-deg incline during this off-road run). The Duratrac tires work great in nearly every condition. We have tested these tires in the snow and mud on other trucks, and they never seem to lose grip. The transfer case offers 4WD high and low ranges, and the automatically locking rear differential helps out when traction is at a premium. Hill-descent-control is there in case you need help on the way down.
Not everything is perfect. The All-Terrain X comes standard with the front chin spoiler. It’s removable, but the truck we tested had it installed and it rubbed on some obstacles. The other clearance problem is the now-larger DEF tank that is mounted on the passenger side and protrudes below the frame rail (the tank volume was increased from 5.3 to 7 gallons). The DEF tank has a steel protection skid plate, so chances of damaging the tank are minimized. GM did not get the opportunity to redesign or move the DEF tank for the 2017 model year.
GM invited TFLtruck (and other journalists) to south-western Colorado for a first drive of the 2017 Sierra HD All-Terrain X and chose the off-road trail for us to use. The truck did not break much of a sweat on this moderate trail. How does it compare against competitor’s off-road heavy trucks? This first drive did not offer the opportunity the push the truck near its limits. Competitor’s trucks were not available for comparison.
The fully-loaded All-Terrain X you see here has an as-tested price of $69,260 (including destination charges).