GMC and American Expedition Vehicles (AEV) have taken the newly launched Sierra HD AT4X to the next level of off-road capability with a new concept build.

Debuting at the 2023 SEMA show, the Sierra Grande concept adds even more overlanding hardware to the Sierra HD AT4X, which launched for the 2024 model year as the top off-road edition of GMC's heavy-duty pickup sporting a 1.5-inch suspension lift, Multimatic DSSV spool-valve dampers, a rear e-locker, and upgraded underbody protection. 

The AT4X is already available from the factory in AEV Edition form, with some parts from the aftermarket company. The Sierra Grande retains the AEV Edition's stamped steel front bumper, but with an additional brush guard. Four AEV 7000 series off-road lights and a winch are also mounted on the front bumper.

GMC Sierra Grande concept

GMC Sierra Grande concept

The suspension keeps the factory 1.5-inch lift, but new fender flares help created additional clearance for larger tires, which lift the truck even higher. A set of 40-inch BFGoodrich tires mounted on AEV Salta XD wheels replace the stock 35-inch Goodyear Wrangler Territory Mud-Terrain tires.

An 8-foot aluminum tray bed replaces the stock bed and incorporates a vertical spare-tire mount. At the back, the Sierra Grande features a custom AEV rear bumper with its own winch.

GMC Sierra Grande concept

GMC Sierra Grande concept

The Sierra Grande has the 6.6-liter Duramax turbodiesel V-8 that's optional for the stock AT4X. It now breathes through a snorkel, but that appears to be the only modification related to the engine, which produces 470 hp and 975 lb-ft of torque in stock form. The power is routed to all four wheels through a 10-speed automatic transmission. A gasoline 6.6-liter V-8 with 401 hp and 464 lb-ft of torque is also available on the AT4X AEV Edition from the factory.

While the Sierra Grande is just a concept, it's possible that something similar could be created by digging into AEV's catalog. GMC also offers AEV Editions of the Sierra 1500 and the midsize Canyon for buyers looking for a smaller factory overlanding rig.