2023 GMC Sierra 1500 AT4X Overlanding Review: Luxury and Performance for Four-Seasons

In this “2023 GMC Sierra 1500 AT4X Overlanding Review,” we put the pickup to the test to see its performance for serious four-season overlanding or expedition use. Heading out into the snowy backcountry during the middle of winter while towing a suitable trailer, driving snow-covered backroads, and spending several days camping in sub-freezing temperatures allowed us to reveal the strengths and weaknesses of this impressive combo quickly.

The overlanding combination I had the pleasure to try out this winter was behind the wheel of the luxurious and highly off-road-capable 2023 GMC Sierra 1500 AT4X towing an equally impressive Imperial Outdoors Xplore X145 overlanding trailer we picked up at Technique Vehicle Outfitters in Bend, Oregon. (Click here to see our review of the Xplore X145.) 

GMC AT4X A Luxurious 4WD Ride

GMC’s 420hp AT4X (MSRP: $81,700) is the most powerful, technologically advanced, and richly appointed four-wheel-drive pickup for off-roading in the GM portfolio. It oozes luxury the moment you open the doors and rest your eyes on the jet-black Obsidian Rush leather seating and Vanta Ash Wood trim. 

The front seats offer exceptional comfort with superb side bolstering and support. They boast heating capabilities which are incredibly convenient during sub-freezing weather and can also be cooled. The seats feature 16-way power adjustments and a multitude of massage options, providing an extraordinary driving experience both on and off the road.

The outside rear seats are also heated and flip up to provide backseat storage for coolers, sleeping bags, and backpacks.

AT4X Loaded With High-Tech Electronics

Then there’s the AT4X’s infotainment system that provides a huge 13.4-inch touch screen to give you a full array of mapping, music, and layers of other information at the touch of a finger. Another helpful feature is the 15-inch heads-up display, which helped me navigate easier in unfamiliar cities day and night.  

The big screen is a joy when backing up to the trailer hitch. The high-definition rear camera in the tailgate allows you to maneuver flawlessly under the trailer tongue. The multi-camera system also gives you a 360-degree top view of the truck and immediate surroundings and side views when the turn signals are activated. The AT4X’s safety features, overall, are excellent.  

The infotainment system’s wireless connectivity with Apple and Android phones is almost effortless. Additionally, the built-in Google compatibility allows you to quickly find just about anything, from gas stations to restaurants to parks to U.S. Forest Service and BLM offices. GMC’s wireless phone charging pad in the center console is a handy convenience item, too. 

The AT4X’s 12-speaker Bose surround-sound system with Centerpoint stereo pumps out plenty of power but seemed a little muddy in sound quality even after adjusting the equalizer controls. We also used the Kicker sound system in the drop-down step tailgate a couple of times at camp. 

A Premium Suspension Package

The AT4X package boasts an extensive range of luxurious amenities and top-of-the-line electronics. However, its suspension and drivetrain are particularly noteworthy for their exceptional performance in towing expedition-style trailers on any terrain.

The 420hp, EcoTec3 6.2L V8-powered GMC AT4X 1500 has a factory-installed 2-inch lift, 33-inch Goodyear Wrangler Territory mud tires, longer travel springs, and Multimatic DSSV spool-valve shocks, all specifically tuned and matched into one of the best factory off-road pickup suspensions you’ll ever find. 

This model has just enough upgrades underneath to remove the harsh jostling and jarring common to the typical 4×4 pickup driving over rougher backroads. Get it into rocks and challenging four-wheeling, and the AT4X two-speed transfer case has electronic driving “mode” selections to allow even more driver control, including Hill Descent.     

The off-pavement ride and handling transition perfectly to highway ride and handling. The ride is smooth, controlled, and forgiving when this truck goes through dips, off-camber sections, hits potholes, encounters speed bumps, or transitions from parking lots to streets.

Class-Leading Off-Road Performance 

GM also took the AT4X to the highest level of off-road capability by equipping it with front and rear electric-locking differentials. Switches on the dash allow you to instantly lock the front and rear differentials when the drive-mode knob is in Low 4WD. 

Although I kept the mode switch in “Auto” during most of my driving time, I turned on the rear E-locker several times in Hi 4WD when pulling the 6,000-pound Xplore X145 trailer up several short, steep sections of snow-covered, rocky, rutted desert backroads. The added traction of the locked rear differential was instantly noticeable.

Being able to lock the front and rear differentials on command and having an automatic two-speed transfer case is excellent for off-road driving. These tools provide exceptional traction and make rugged off-pavement excursions less dramatic. They outperform less capable 4x4s that would struggle to continue on.

AT4X A Little Weak On Towing Capacity

The trade-off for a more supple and longer travel suspension designed to maximize off-pavement traction is a lighter towing capacity than the AT4X’s ½-ton stablemates. The short-box Crew Cab AT4X has a maximum trailer towing capacity of 8,900 pounds. The standard 4WD 1500 Sierras with the 6.2L EcoTec3 V8 are rated at 13,000 pounds.

This lighter towing capacity means the GMC Sierra AT4X can tow all but the largest overlanding/expedition-style trailers on the market. For example, the Xplore X145 being towed on this outing weighed in at 6,172 pounds GVWR. The AT4X handled it with ease. 

GMC Sierra AT4X Overall

There’s little not to like about the 2023 GMC Sierra AT4X. It has gobs of power, a terrific ride, and is as plush as one could want in a pickup that will probably see more mud, dirt, sand, and snow than most 4×4 pickups. 

The creature comforts, electronics, safety features, and towing-related Apps that come with the AT4X are first-class. There are so many features that it’d take an owner weeks to start figuring out what all is available and what everything does. For example, the In-Vehicle Trailering App does everything from automatically checking trailer lights to giving maintenance reminders.

Even the fuel economy is good, considering the healthy 420hp 6.2L gas V8 under the hood. The EPA numbers (14 city/17 highway) are average for a ½-ton pickup running a 420hp V8. GM’s Stop/Start technology helps maximize city mileage. 

During my time in the truck driving over the Cascade Range, spending several days in Oregon’s High Desert towing the X145 trailer, and a mix of city and highway driving, the AT4X averaged 15.6mpg—and on a 100-mile freeway drive, running empty with adaptive cruise control at 65mph, the AT4X average 18.4mpg. (Highway trailer-towing fuel economy averaged 13.4mpg).

A Couple AT4X Nits To Pick

After spending a week and more than 500 miles behind the 2023 AT4X Sierra 1500, I only had complaints focused on the multi-function “MultiPro Tailgate” and the dealer-installed rocker rails.  

The rock rails ($1,195 option) do the job nicely, but the version installed on this truck didn’t provide safe footing. This was an issue for those who needed to hoist themselves into the cab, particularly in wet, snowy, or muddy conditions. Power running boards, like those from AMP-Research, would be a much better dealer-installed option.

The multi-function tailgate, standard on this model, provides a lot of configurations for hauling and easier access into the bed. But releasing the upper portion so it flips out to be a step – and closing the step to close the tailgate — is a pain. GM needs to devise a smoother way to handle the drop-down step operation. 

Despite those two annoyances, there isn’t a plusher, more capable full-size GM 4WD pickup. It’s perfect for those planning to take roads less traveled and enjoy the overlanding/off-road life. The 2023 GMC Sierra 1500 AT4X is a keeper.       

Editor’s note: MSRP is subject to change