Driven: 2022 GMC Sierra AT4X Offers Glamping For Off-Road Enthusiasts

Off-roading continues to grow in popularity around the country and GMC is responding with an all-new trim for its full-size truck. While the new Sierra Denali Ultimate is heavily geared toward luxury, the new Sierra AT4X that’s an even fancier version of the existing AT4 trim is meant to be the most premium off-road-focused truck that the brand has ever made aside from the Hummer EV.

After a day in the desert and subjecting this truck to triple-digit temperatures we’re confident that it’s a reason for glampers (glamorous campers) to rejoice.

Adding An X Makes Everything Cooler

Quick Facts › › ›

It wasn’t long ago that GMC introduced the AT4 trim level across much of its lineup and today it even extends down to the Terrain AT4 SUV. Each model gets a different combination of off-road gear and the Sierra AT4 is already one of the most capable. The AT4X takes things to a new level with more extreme equipment meant specifically for going off the paved road.

Unlike the AT4, which uses a Duramax diesel engine as its base option, the AT4X is only available with a 420 hp 6.2-liter V8. In addition, the AT4X utilizes Multimatic DSSV dampers, twin-tube shocks, and electronic locking differentials in the front and the rear. It features a 25.5-degree approach angle, a 23-degree departure angle, and a 22.7-degree breakover angle.

At the same time, the AT4X is meant to be more luxurious than the AT4 too. GMC says that it achieves that goal through the use of open-pore wood trim on the doors and special interior trim that’s easier to clean. It also has massaging seats which are superb.

Cameras are a large part of the appeal as well. Though not exclusive to the AT4X, a full surround camera network allows drivers to see a forward view, as well as the conditions on each side of the vehicle, in the bed, and behind the truck. GMC’s MultiPro tailgate makes an appearance too and in the AT4X it even has a Kicker Bluetooth audio system hidden inside. Save for the even more powerful and more extreme Hummer EV, GMC has never made a truck as luxurious, full of features, and capable off-road as the AT4X.

An Exterior That Tricks The Eye

While it’s not a revolutionary change over the 2021 model, the 2022 Sierra gets a new grille that’s meant to make the truck look even wider than it already is. The headlights also have slight changes so that they blend into the grille more smoothly. Of course, this truck is wide anyway. Back in 2000, the heavy-duty Sierra 3500 was 77 inches wide. This truck is even wider, at 81.2 inches.

Aside from those relatively slight changes, the Sierra looks very similar to last year’s model. Just like the AT4, it features a 2-inch factory lift kit but exclusive to the AT4X are 18-inch gloss-black wheels. A full-size spare with a factory wheel is included and stowed underneath the bed. There are lots of AT4X badges too. You’ll find them on the tailgate, each front door, in the bed itself, on the grille, in the door sills, on the seatbacks, and on the door cards too. Buyers can be sure that they won’t be confused with the regular AT4.

Luxury For Five

While the seats in the new Denali Ultimate look and feel just a touch nicer, the AT4X doesn’t lag far behind. It still uses the same full-grain leather upholstery and massaging seat technology but adds a coating to the surface that’s meant to be easy to clean after a long day in the desert or mud. The accompanying trim throughout the cabin shares the same focus including the rubberized floor mats and the button-on/off fabric centerpieces for those floor mats.

Anyone familiar with the infotainment system in the new Hummer EV will immediately recognize the setup in the AT4X. We’ll get into functionality below but the screens themselves are identical in size and location to the Hummer. The steering wheel is also similar to previous GM products and features nearly 20 buttons when counting the paddle shifters. The gear shifter itself is chunky and perhaps overly large. It’s not physically connected to a shift lever so we think a dial or buttons like the new Yukon Denali Ultimate might’ve been a better use of space.

Interestingly enough, GMC has placed the trailer brake controller right beneath the shifter. The brand argues that it wants that feature easy to find and use but it seems odd to place it so prominently. The rest of the cabin is unquestionably good though. A long deck of switches that GMC calls the ‘piano keys’ are laid out underneath the climate controls. It includes important functions like parking sensors, electronic locking differentials, traction control, hill-descent control, and more. The start button is indeed gigantic and perhaps the only part in the cabin that can still be compared to a big Fisher-Price toy.

Climate is primarily controlled through physical buttons, switches, and knobs just above the ‘piano keys’ and it works great. We spent hour upon hour out in the desert and while exterior temperatures reached 111-degrees Fahrenheit the truck kept things in the high 60s without issue all day. Ventilated seats add to the comfort and a microsuede headliner along with matching A-pillars is nice to look at.

More Technology Than You Can Throw A Rock At

Enter the AT4X and you’ll be greeted with a unique welcoming video that utilizes both the infotainment screen and the driver information display, not unlike the one you’ll get in the Hummer EV and the Denali Ultimate. GMC will be quick to point out its sizable heads-up display that’s standard in both new trims but in our testing, it wasn’t as good as it could’ve been.

While the size is excellent and the information on display is important, it was far too dim to use in bright conditions. Direct sunlight on or around the vehicle would cause the heads-up display to be almost totally washed out to the point that we quit trying to use it for the most part. At night time it should be no real issue though.

The infotainment system itself is quite good and the new integration of Google Built-In is a nice feature that many will enjoy using. Unlike hooking up Android Auto and being somewhat locked out of some user interface features, Google Built-In provides a seamless experience regardless of the activity you’re trying to engage in. The only downside is that with a screen so large we’d like to see it capable of doing more than a single task at once. It’s frustrating that things like navigation can’t remain on the screen when a user wants to swap radio stations or adjust the massaging seats.

The premium Bose sound system is above average to our ears. It produces excellent tonal quality and clarity throughout the truck. We also like the addition of a Kicker Bluetooth speaker in the MultiPro tailgate. Along with a household-style outlet in the bed and another 12-volt power outlet in the tailgate itself, it’s a highly versatile space we can imagine using in a number of different ways.

Chevrolet also outfits the AT4X with a number of advanced driver assistance aids including full-speed adaptive cruise control and lane-keep assist. It does not get the brand’s impressive SuperCruise technology though. GMC told us that while the new Denali Ultimate has revised bumpers and engineering updates to accommodate SuperCruise, the AT4X currently doesn’t have the same features.

It did also say that as a brand it’s always considering customer feedback and interest so at some point down the road the AT4X might end up with SuperCruise. Thankfully, the adaptive cruise control does a good job of mimicking many of that technology’s actions. In our testing, the only issue we found was that braking took longer to begin than what we were comfortable with in most situations. At times, the truck was simply traveling too quickly towards nearly stopped or stopping traffic for us to allow the system to finish the job so we took over.

How The AT4X Handles The Urban Environment

Initially, the high ground clearance and tall driving position can make the AT4X a bit of a bear to drive. It’s tough to see exactly where your corners are and while the cameras are always available, they’re not something that we imagine most will use in daily practice for navigating around town. Get a few miles under your belt though and the Sierra starts to feel more comfortable and easier to predict. The steering is perhaps just a bit lighter than we expected but the suspension is sincerely impressive on the road. The brakes respond quickly and accurately with linear feedback and good bite when you need them.

The accelerator isn’t as smooth and at times produced somewhat jerky movements at lower speeds despite smooth pedal engagement. On the other hand, once up to speed, the AT4X is far more comfortable than an off-road focused vehicle has any right to be. The 10-speed automatic transmission shifts smoothly and effortlessly and the 6.2-liter V8 finds its groove at higher speeds where it’s happiest. Thanks in large part to the Multimatic DSSV dampers, the ride is sublime and only the very worst road conditions produce harsh vibrations.

In addition to the excellent suspension tuning, the rest of the truck does a nice job of keeping road noise out of the cabin. Both the front and rear seats have more than enough room for five adults to stretch out and relax. Thanks to a thoughtful indentation in the interior headliner, even tall adults should have no issue with headroom in the back seats either. GMC offers an optional storage box that goes underneath the rear seats but we’d skip it as there’s already space under each one for extra gear should you want to use it.

When The Road Runs Out

To find out how the Sierra AT4X would handle real off-road situations GMC took us to Diablo Drop Off in Anza Borrego Desert State Park, California. The most prominent feature of the trail is a relatively steep downhill section of gravel with deep gouges that require quite a lot of articulation or some excellent rock sliders to traverse properly. Thankfully, the AT4X has both in addition to 10.9 inches of ground clearance but we’ll come back to that.

Before anyone can get to Diablo Drop Off they’ll need to traverse miles of off-road gravel, sand, and rock. It’s over this distance that the Sierra AT4X might have been the most impressive because despite going over some pretty huge bumps and holes in the road at speeds in excess of 40 mph (64 km/h) at no point did it ever bottom out or hit the bump stops. In fact, oftentimes the faster we went, the more comfortable the ride was.

On tight technical sections where the canyons converged to make the road nearly impassable the exterior cameras made for excellent spotters. Going up and down some of the more extreme obstacles before Diablo Drop Off offered a good opportunity to try out the rock sliders which are a $1,150 option but should be standard. We say that because Diablo Drop Off made full use of them.

The actual drop-off sees you descend roughly 100 feet at a 45-degree angle during its most extreme section. It’s not as steep as the off-road obstacles that Mazda had us try in the CX-50 but the large gouges in the terrain were the real challenge. The AT4X had no problem with them and each of the 10 trucks we brought out made it up and down the feature twice without a single issue whatsoever. The rock sliders came into play on each descent so we wouldn’t want to imagine the damage that could’ve been caused without them.

Keep in mind too that after more than an hour out in the hot 111-degree Californian desert testing on Diablo Drop Off we still had to drive back to civilization. Thankfully, the Sierra shuttled us back to the paved highway without issue. As we took a different path back we had even more opportunities to try out the camera systems and the way that this pickup handled larger rocks. Plenty of obstacles slowed us down in an effort to avoid leaving paint behind but nothing stopped the truck.

Despite all of its ruggedness, it should be stated that the AT4X is special not because it’s capable off-road but because it’s capable while also being luxurious and comfortable. After all, a Google review from just a few weeks ago indicates that a Jeep Grand Cherokee (WJ) with a two-inch lift and all-season tires could conquer Diablo Drop Off without issue. We can assure you that those folks weren’t getting a massage on the way down like I was though.

The New Gateway

The Sierra AT4X isn’t the most comfortable truck in the history of trucks and it isn’t the most capable off-roader either but it’s one of the few vehicles that can confidently claim to achieve both at a high level of competence. When we think of what it means to have the luxury of off-roading in this particular fashion it’s about more than massaging seats.

It’s about having the freedom to go on your own and knowing that the cameras can do quite a lot of the spotting for you. It’s knowing that you don’t have to bring extra speakers for the campsite. And it’s knowing that this rig is just as happy to crawl around rocks as it is to play desert runner. We can’t think of a better gateway to off-roading for the aspiring glamper even if that comes at a cost, and to be precise, from $74,995 before any options.

Photos Stephen Rivers for Carscoops.com / GM