GMC is adding a top-end off-road AT4X trim to the 2024 heavy-duty Sierra pickup starting this fall.
The AT4X trim already is offered on the Sierra light-duty full-size pickup and the Canyon midsize pickup. It will debut on the freshened 2024 Sierra HD with a 1.5-inch suspension lift installed at the factory, along with Multimatic DSSV dampers, a rear e-locking differential, 35-inch tires, a larger steel transfer skid plate and front aluminum skid plate, and unique front upper and lower control arms and steering knuckles, GMC said.