GMC has been rolling out variants of their trucks that have been slightly enhanced for off-road driving. What started with the Canyon and Sierra 1500 now comes to the GMC 2500 platform with the 2017 Sierra HD All Terrain X.

We already appreciate the GMC Sierra 2500HD, especially when it's powered by the 6.6-liter V-8 turbo diesel and Allison six-speed transmission, so there's no questioning the platform. This is a beefy work truck run through GMC to add more interior and appearance upgrades from its Chevrolet Silverado relative.

And we've heard more and more government agencies are adding GMC pickups to their fleets.

The All Terrain X package adds more aggressive tires, additional LED lighting, and a black appearance package. The upgrade may not draw more budget-conscious fleets, but it does add to the fun of the entire package. The All-Terrain X package adds about $2,990 to the sticker, while the All-Terrain package adds $1,850.

Here's what you get. The All-Terrain package adds black-painted 18-inch wheels, mud terrain-rated Goodyear Duratrac tires (LT275/65R18), power folding and heated mirrors, four assist steps, and a sport bar.

The All-Terrain package adds the Z71 off-road suspension with twin tube Rancho shocks, an underbody shield, hill descent control, spray-on bed liner, heated steering wheel, leather-appointed front bucket seats, and additional USB ports and wireless charging.

The truck arrives with a GVW of 10,000 pounds and carries a rear axle ratio of 3.73.

We tested the SLT trim model with 4WD and a crew cab that would retail for $69,765.