The AT4X is even more focused on off-road performance than the trail-tackling AT4. On top of the AT4's upgrades — which include four-wheel drive with low range, protective skid plates and General Motors' unique one-pedal off-road driving — the AT4X comes with specialized shock absorbers, electronically locking front and rear differentials, and 32-inch all-terrain tires. This is similar hardware to what's on the 2022 Chevrolet Silverado ZR2 off-road variant, though by comparison the AT4X is toned down. It has a more street-friendly front bumper that sacrifices approach angle for style, and the tires are a step lower on the extreme scale from the ZR2's 33-inch mud-terrains. Still, the AT4X proved plenty capable over rough terrain, scaling steep dirt inclines and tackling deep ruts with ease thanks to soft cushioning from the advanced suspension dampers by Canadian company Multimatic. It's the first time I've personally off-roaded while enjoying massaging seats as well.
Besides massaging seats, highlights of the AT4X's cabin include a suede headliner, upgraded leather and a 15-inch head-up display. You'll also get these features and more on the new Denali Ultimate level, which is the pinnacle of the Sierra 1500 lineup. It doesn't have the AT4X's off-road hardware, but it does carry forward many of that truck's interior appointments. It also has unique extras such as laser-etched open-pore wood and extended use of upgraded leather throughout the cabin. The truck makes a strong luxury statement with 22-inch wheels and a black chrome grille, while GMC also includes its full suite of flashy features like a carbon-composite bed, adaptive suspension dampers and power-retractable side steps.
How comfortable is the Sierra 1500?
In its Denali Ultimate trim, as to be expected, the Sierra 1500 is a very comfortable truck. There is impressive sound deadening inside the cabin that prevents noise from the road, wind and engine from interrupting your cruise. The adaptive suspension also works well, helping the heavy pickup rebound from bumps and cracks in the road. Unlike some other adaptive systems, though, this one only reacts to the road it encounters — it cannot scan ahead and prepare for imperfections in advance. So you do feel the road through your seat, more than in some versions of the Ram 1500, for example. Still, the Denali Ultimate and its more plush aspects stand out in the class.
As for the AT4X, it feels immediately more comfortable than its Silverado ZR2 cousin. This is largely due to the smaller, less aggressive all-terrain tires that emit less noise and muffle some bumps in the road. But the luxury trimmings in this off-road truck can't be denied. Soft materials abound, and both heated and ventilated front seats are always welcome off the beaten path.
How's the Sierra 1500's interior?