The 2024 model year is a big one for the GMC Sierra 2500HD. A new Denali Ultimate trim point debuts for those who want a limousine disguised as a truck. And, more in my wheelhouse, the new AT4X off-road package debuts.
The 2024 GMC Sierra 2500HD AT4X is direct competition for the storied Ram Power Wagon. But it’s not really a close call as to which is the better off-roader.
There are two off-pavement packages for the Sierra 2500HD. The AT4 is the lighter-duty off-road option, with hill descent control, off-road suspension tuning (but still stock), some skid plates, recovery hooks, and 20-inch wheels. This is the setup when you want to look rugged and ready, but don’t actually need to be all that ready.
The AT4 is a good off-road rig as-is for most light and medium-duty stuff like bouncing around Vedauwoo or getting through the latest blizzard in Hanna. And the AT4 package doesn’t lift the Sierra 2500 enough to interfere with gooseneck or fifth-wheel pulling. Other HD off-road trucks, including this one, can have trouble with that.
But if you have a budget that can include a term like “Denali” in your purchase decision, there’s now the AT4X package. Which is much more all-terrain ready. It builds on what the AT4 has with a raised suspension and advanced adaptive dampers. Plus even stronger underbody plates, a locking rear differential, and more knobby all-terrain tires.
The optional AEV package from American Expedition Vehicles adds little bison logos along with 18-inch wheels (easier to find better A/T tires for), heavy-duty bumpers, and some accessory switches for things you’re almost assuredly going to add. Like bar lights, a winch, and whatnot.
From the factory, the 2024 Sierra 2500HD AT4X has a 1.5-inch suspension lift, giving it a ground clearance of 11.6 inches. For comparison, the current-generation Power Wagon has a two-inch factory lift, resulting in a 14.2-inch ground clearance.
Whatever Sierra 2500HD model you choose, a turbocharged 6.6-liter gasoline or diesel engine will be powering it. A 10-speed automatic transmission is also standard. Four-wheel drive is optional on most trims, but standard on all off-road and luxury trim points. I drove the diesel, which I would prefer were I the one buying. Especially the Duramax and 10-speed combination that has been so beautifully tuned in General Motors’ lineup of trucks.
On the road and with that diesel setup, the 2024 GMC Sierra 2500HD AT4X is smooth and comfortable. Smoother than most off-road-centric rigs are. The combination of all those gears plus the well-done suspension tuning via those adaptive dampers is why that is.
Off the road, though, the AT4X shows through as a great design for heavier off-pavement activities. Without a disconnecting sway bar, better approach and breakover angles, and a front locker, though, the AT4X falls short of the Power Wagon. The tradeoff for a smoother ride and more upscale and tech-savvy interior. The Sierra 2500HD AT4X and the 2500 Power Wagon have a similar starting price, roughly $80,000, so the choice as to which you’d want really comes down to what you want to do with it.
The Power Wagon is the Jeep Rubicon of heavy-duty off-road rigs. It’s the benchmark when it comes to equipment and capability. The AT4X, however, is more the Land Rover of off-roading. It’s more luxurious, far more capable than expected, and a lot more comfortable to drive every day.
Either way, you’re getting an off-road-ready heavy-duty truck that you’ll have to put a fifth-wheel riser on to haul your camper.
