2024 GMC Sierra 2500HD AT4X First Look: GMC’s Power Wagon Rival

The AT4X will be offered with gasoline and diesel engines. The former is a 6.6-liter gasoline V8 that makes 401 horsepower and 464 lb-ft of torque, while the turbocharged 6.6-liter V8 diesel makes 470 horsepower and 975 lb-ft of torque. Both engines are mated to a 10-speed Allison automatic transmission. Max conventional towing for the AT4X is rated at 18,500 pounds should you opt for the standard AT4X with the diesel engine. Gas-powered AT4X models can tow up to 16,000 pounds. Gooseneck trailering is rated at 18,000 pounds for the gas AT4X and 17,300 pounds for the diesel.

The cabin is exactly what we’ve come to expect from GMC: a slightly zhuzhed-up version of the Silverado’s interior. There’s an exclusive color scheme called Obsidian Rush and, as you might imagine, it’s all blacked-out. It also includes massaging full-grain leather seats, a 12-speaker Bose sound system and wood decor. The dashboard is dominated by the 13.4-inch infotainment display we’ve seen in other Sierras and is partnered with a 12.3-inch customizable digital instrument cluster and 15-inch head-up display.