- Off-road-themed AT4X joins the updated Sierra 2500HD lineup for 2024.
- Upgrades include an upgraded suspension and 35-inch mud-terrain tires.
- A new AEV Edition is available, too.
Driven: 2024 GMC Sierra HD AT4X AEV Edition Climbs Mountains and Can Pull One Too
Yes, heavy-duty off-road trucks are now a thing
Elon Musk memorably prefers short names, whether Tesla's single letter lineup or that thing we used to know as Twitter. Then we have the 2024 GMC Sierra 2500HD AT4X AEV Edition, which comes close to rivaling "supercalifragilisticexpialidocious" for being a mouthful. But hey, when you've built a truck that can tow up to 18,500 pounds and go off-road like a boss, you've earned the right to name it whatever you want.
For starters, GMC has given the Sierra HD a handful of notable upgrades for 2024. The standard 401-horsepower gasoline-powered V8 receives a new 10-speed automatic transmission instead of 2023's six-speed. The extra gears should be useful for better optimizing the truck's power delivery for both around-town cruising and towing. Still optional is a turbocharged 6.6-liter V8 diesel engine but it's slightly more powerful this time around: 470 hp and 975 lb-ft of torque compared to 2023's 445 hp and 910 lb-ft. Inside the revamped cabin is a new infotainment setup that includes an available 13.4-inch center touchscreen and 12.3-inch digital instrument panel.
More capability for when the road ends
The Sierra HD also gets a couple of new trim levels: the full-luxe Denali Ultimate and the off-road-oriented AT4X. The latter is only available for the Sierra 2500HD (not the 3500HD) and is the one we briefly got to test-drive.
Equipping a heavy-duty truck for off-road duty isn't necessarily logical but there's obviously a market for it — one that Ford has recently gotten into with its available Tremor package for its Super Duty trucks, and Ram with its 2500 Power Wagon. Some truck owners want a pickup that's more capable for overland-style driving while others just desire a better match for pulling a big fifth-wheel hauler full of off-roading toys.
Special hardware upgrades for the four-wheel-drive AT4X include a 1.5-inch suspension lift, 35-inch mud-terrain tires, trick Multimatic DSSV suspension dampers, revised front suspension components, larger underbody skid plates and a locking rear differential.
Still not rugged enough for you? OK, then check out the new AT4X AEV Edition. AEV refers to American Expedition Vehicles, a well-known aftermarket off-road parts company. On top of the AT4X, it has steel bumpers with heavy-duty recovery points, heavy-duty steel underbody skid plates, tough-looking black-painted wheels and distinctive interior trim.
Much like taking an ice bath, intentionally directing a full-size truck that weighs approximately 8,000 pounds into the dirt is not something that seems inherently natural or fun. But the results are surprising. On an open terrain trail, the Sierra 2500HD AT4X AEV tackles ruts and dips with little trouble. It can be hard to see close-up terrain because of the truck's broad, high-set hood but thankfully there are sharp-looking forward and surround-view cameras that help you spot what's close by as you approach.
The Sierra 2500HD AT4X AEV joins its corporate sibling, the Chevrolet Silverado 2500HD ZR2 Bison, as well as Ford's similar Tremor-equipped Super Duty and Ram 2500 Power Wagon in offering credible off-road capabilities. Among this group, it should be pretty compelling for truck shoppers wanting a rugged and pretty luxurious HD truck.