Throughout the course of automotive history, there are a few certainties. The first is that there is no sound on earth like a small block V-8 growling through a free-flowing exhaust, the second is that no matter when you wash your car, a storm or a bird with a free-flowing exhaust is never far away, and finally, there is no rivalry fiercer than the pickup truck market. Whether it is Ford, Chevy, or Ram, each respective customer base is nearly as resolute as a political or religious following. But much in the same way that there are more than just “the big three” of each of those groups, we often forget that there are also other pickup trucks vying for a piece of the consumer pie. For 2024, one of those parties is the GMC Sierra 2500 HD.
Generally, with pickup trucks, the game plan is to show off either a truck’s work ethic or its fun-loving off-roading prowess. But it seems that GMC has decided to combine both of these powers into one very exciting, and capable truck known as the Sierra 2500 HD AT4X. Normally reserved for its other models, 2024 is the first year a Sierra HD gets the off-road badge. Specifically, the AT4X can only be ordered if the 2500HD has a standard-length bed and come with a crew cab.
The AT4X comes with a suspension that gets raised up a full 1.5-inches, sitting on trick Multimatic DSSV spool-valve dampers that not only allow the Sierra to deal with any sort of off-road terrain, while still being able to provide a very comfortable and responsive on-road ride. Of course, the big 18-inch black wheels shod in massive 35-inch Goodyear Wrangler Territory M/T rubber look more Baja than ballet, but those fancy shocks have three separate spool valves to ensure passengers will never have anything to complain about.
The AT4X comes to the table with beefed-up steering knuckles as well as trim-specific upper and lower control arms up front as well as an electronically locking rear differential out back. To keep things in between those two ends safe, GMC installed both a front skid plate as well as better protection for the transfer case as well.
Power for the 2024 GMC Sierra 2500 HD comes in two strengths: tough and tougher. The standard issue engine is a gas-powered 6.6-liter V-8 that produces a solid 401 horsepower and 464 pound-feet of torque or you can have a 6.6-liter Duramax V-8 that produces a whopping 470 horsepower and a ridiculous 975 pound-feet of torque. In either case that power is then sent through the same Allison 10-speed automatic transmission and then onto all four wheels, as you cannot get either the AT4X or AEV as a rear-wheel drive-only setup.
The 2024 GMC Sierra 2500 HD AT4X is still built to work, and as such, can hold its own against any competitor out there. At its best, the AT4X has a maximum payload of 3,291 pounds, and adding a fifth-wheel/gooseneck brings the towing capacity up to an impressive 18,000 pounds. Being able to tow something of that magnitude, GMC also includes Transparent Trailer View, Adaptive Cruise Control with Trailering, Trailer Side Blind Zone Alert, and 14 total camera angles to make sure your cargo stays where it should.
Inside, the 2500 HD AT4X offers up an almost plush interior with things like leather-wrapped seats that come with a power massaging feature, and a premium 12-speaker Bose stereo system that is operated by a huge 13.4-inch infotainment touchscreen. The driver is privy to a big 12.3-inch info screen as well a 15-inch head-up display.
Although GMC has not yet announced pricing for the AT4X at the time of this writing, we expect a base price of around $90,000, which keeps it on par with all the competition. The main competitors to the Sierra HD are the Ford F-250 Super Duty, The Ram 2500, Chevrolet Silverado 2500 HD, Toyota Tundra, and the Nissan Titan XD. The 2024 Sierra 2500HD AT4X may not be the first name that comes to mind when pickup trucks are involved, but perhaps it should be.