Truck Review: The GMC Sierra AT4X Blends Luxury with Off-Road Capability
General Motors built the GMC Sierra AT4X for smooth rides on and off pavement
In today’s automotive world, there are generally three types of full-size trucks: blue collar workhorses, rough and tumble off-roaders, and high-end highway pickups that can handle off-pavement adventure, but rarely leave the blacktop. These categories don’t often overlap into a single truck, and when they do, they require compromises that usually result in a less-than-stellar offering that fails to do anything as well as a purpose-built pickup. General Motors attempted to straddle two of the truck categories with its new GMC Sierra 1500 AT4X, a luxury truck that is a capable off-road 4×4.
Dedicated off-road machines are becoming more and more common, and truck trim lines such as Ford’s Tremor, Ram’s Rebel, Toyota’s TRD Pro, and GMC’s own AT4 line testify to this fact. A truck that can get you from point A to B across virtually any terrain is a big draw for consumers, hunters and anglers included. While these trucks may be great for muddy trails and rutted roads, they lack a little in the refinement department.
Maybe you’re a hunter who loves the idea of a high-end truck in the great outdoors, but as newer trucks get saddled with more comfort and technology, they often lose their off-road chops. Sure, you could take a new Denali along for your next duck hunt, but the thought of tackling that rough and rutted two-track to the blind might leave you stuck in the mud.
GMC’s new AT4X version of the half-ton Sierra attempts to straddle the line between comfort and capability, combining the AT4’s attitude with the Denali’s refinement while throwing an extra cherry or two on top. But will the platform succeed?
Sierra AT4X Specifications and Features
As expected, the GMC’s half-ton AT4X packs plenty of top-notch features and off-road goodies. Standard features include:
- 6.2-liter Ecotec V8
- 10-speed automatic transmission with electronic console-mounted shifter and paddle shifters
- Two-speed transfer case
- 3.23 electronic locking rear differential and first-in-class front electronic locking differential (not counting the Chevy Silverado ZR2)
- 18” wheels with 32” Goodyear Wrangler DuraTrac A/T tires with matching spare
- Off-road tuned Multimatic DSSV spool-valve dampers (shocks)
- One-pedal off-roading capability (Terrain mode, 4WD LO)
- Two-inch factory lift
- 11.1-inch ground clearance
- Improved approach and departure angles
- Skid plates
- Premium interior
- Premium electronics suite (Google-integrated infotainment system with Android Auto and Apple CarPlay, and roughly 40 inches of screens, including dash and heads-up display)
- Premium extras (including exterior cameras and sensors, wireless phone charger, premium Bose sound system, dual heated and ventilated seats, adaptive cruise control, power seats with adjustable massage feature)
Like most of today’s specialty pickups, the Sierra AT4X comes standard with a crew cab and a short bed (just a hair under five feet, 10 inches long). Like its Chevy counterpart, this Sierra is a large truck, although it lacks to extra girth of Ford’s Raptor and Ram’s TRX. Road visibility is very good, especially with the standard 2-inch lift, although it does have some significant blind spots.
This half-ton Sierra blends distinctive GMC styling with an aggressive look that is similar to the original AT4. The black grille, red tow hooks, black fender liners, black 18-inch aluminum wheels, aggressive all-terrain tires, and the factory lift make this truck look a bit more at home in the mountains than New York City. While the AT4X may lack the aesthetic refinement of a true red-carpet ride, it still looks regal enough for a night on the town.
Inside, the truck displays its Denali DNA, albeit in a subdued way. Like GMC’s luxury trims, the AT4X sports an all-black full-grain leather interior with red and white contrast stitching and a black microsuede headliner. It also includes black ash wood trim and chrome accents to emphasize the truck’s refined side and a few bold “AT4X” badges. The premium electronics suite and sound system round out the ritzy interior.
The AT4X’s ride is smooth for a full-size pickup, and much thanks goes to the Multimatic DSSV dampers for this performance. The 6.2-liter V8 delivers an impressive 420-horsepower and 460 lb.-ft. of torque which translates to a GMC-claimed 0 to 60 time in under six seconds. On the road, the AT4X is almost boring to drive but in a good way. Off road, the motor and dampers provided top-notch performance and comfort even at speeds exceeding 60 miles per hour on southern California’s washboard desert trails.
Most modern full-size pickup trucks come with plenty of off-roading features, such as skid plates, two-speed transfer cases, and all-terrain tires, but the Sierra AT4X includes a few features that make it stand out head and shoulders above all other half-tons. As a mechanical clone of Chevrolet’s ZR2 Silverado, the AT4X comes with Multimatic DSSV dampers and electronic locking front and rear differentials (yes, front and rear e-lockers—that’s a big deal) which is, to the best of my knowledge, a first in the half-ton truck segment. It also comes with three driving modes designed for optimal performance: Normal, Off Road, and Terrain.
The Multimatic DSSV dampers (shocks) use spool valve technology developed from racing and performance vehicles to provide an impressively smooth ride both on and off road. These shocks are specifically calibrated to the factory Sierra AT4X.
The front e-locker is a great feature for providing traction in especially difficult terrain where vehicle articulation matters or where two wheels may be off the ground simultaneously. While it may be overkill for most situations, when you need it, you really need it. When in use, the truck also locks the rear axle, effectively creating two solid axles at the touch of a button.
Finally, the truck comes with two settings dedicated to off-road use: Off Road and Terrain. Like similar settings on other trucks, Off Road mode deactivates certain systems, such as traction control, to give the driver more control over the vehicle. Terrain mode, however, is a little magical. This setting shines brightest when the truck is in 4 Lo with the transmission in manual mode. Terrain mode uses automatic braking to provide the driver with a truly one-pedal off-road driving experience on steep slopes.
What the GMC Sierra AT4X Does Well
GMC went big with the new AT4X, and the payoff is a very capable truck.
- This Sierra’s 6.2-liter V8 delivers plenty of power (420 hp at 5,600 RPM) and torque (460 lb.-ft. at 4,100 RPM), and the paired 10-speed automatic transmission delivers smooth shifts between gears.
- This truck includes all the best off-road upgrades: two-speed transfer case, 32-inch Goodyear DuraTrac all-terrain tires (with matching spare), a factory lift that creates 11.1 inches of ground clearance, and improved approach and departure angles, Hill Descent Control, front tow hooks, and plenty of skid plates.
- All-Terrain tires generate noticeable road noise, but the included Goodyear DuraTracs produce minor road noise that is not at all bothersome.
- The AT4X includes a rare electronic locking front differential, a first in the half-ton truck segment, in addition to the rear e-locker, a first for the Sierra.
- Thanks to the Multimatic shocks, this truck has exceptionally good manners, delivering an impressively smooth, comfortable ride both on road and off.
- GMC successfully delivered a high-performance truck with a rustically refined cabin. The interior’s finish materials and technology upgrades rival even the posh Denali Ultimate. Built-in Google along with Apple CarPlay and Android Auto are nice touches for the tech savvy hunter.
- The new Sierra’s Terrain mode offers true one-pedal for maximum control on steep slopes.
- The AT4X makes even the toughest off-road obstacles too easy.
Where the GMC Sierra AT4X Fell Short
No truck is perfect, and this new Sierra does disappoint in a few areas.
- Easily the biggest disappointment is the AT4X’s low payload rating. With all the off-road goodies, this truck packs on the pounds, limiting payload to 1,420 pounds.
- The Sierra AT4X is a true off-road truck that lacks a bit in the towing department. With a max towing capacity of 8,900 pounds, it will handle ATV trailers, small campers, and a few small boat trailers well enough, but it doesn’t beat out a towing-dedicated Colorado or Suburban by much.
- While the 3.23 axle ratio provides for a relatively fuel-efficient driving experience for a large V8, the lower ratio diminishes this Sierra’s acceleration (somewhat), towing capacity, and rock crawling abilities. That said, the truck still performs well on established off-road trails.
- Some users have reported that early versions of the Multimatic DSSV found on the Chevrolet Colorado ZR2 have demonstrated short lifespans.
- The DSSV dampers lose a good bit of their performance when paired with aftermarket suspension and wheel modifications, such as lift kits or larger tires.
- Getting used to the truck’s electronic shifter takes some time. That said, the paddle shifters are a familiar, sporty addition.
- For a modern pickup, the AT4X features some pronounced wind noise.
- The front-facing camera is a nice idea for off-roading, especially on steep grades or rocky terrain, but in the real world, the center screen displays a fairly washed-out picture that does little to help with 3D perception.
- Terrain mode requires plenty of throttle to overcome the brakes and to get moving even a little bit. This makes it feel very draggy and almost a little painful. Sure, it works, but the experience is not particularly enjoyable. Also, if used often, Terrain mode likely will burn through brakes very quickly.
- Except for white, all paint colors come with a $495 upcharge (or more).
- For most hunters, this may be a small quibble, but compared to the Raptor and TRX, the AT4X’s approach and departure angles are lacking. That said, the Sierra’s angles are nothing to sneeze at.
Very few half-ton pickups can compare to the Sierra AT4X, making it the Denali of off-road trucks both in terms of performance and luxury. Toyota and Nissan’s top off-road offerings can’t touch this Sierra. Ford’s F-150 Tremor does a decent job of challenging the capable AT4, but even a fully optioned Tremor still falls short of the top-of-the-line AT4X. Trucks like the Ford Raptor and Ram TRX are purpose-built desert racing machines with AT4X-like price tags but without the all-around capabilities of the Sierra. That only leaves the ZR2 Silverado, the AT4X’s mechanical clone. For most hunters, a standard AT4 should be plenty of truck. As impressively capable (and luxurious) as the Sierra AT4X is, it is a lot more truck than most hunters will need. It will take you just about anywhere you could ever want to go.
Want your own Sierra AT4X? Then drop by your local dealer and pick one up. With as many goodies as this truck includes from the factory, there is no real need for more than one or two upgrades. That said, I might bolt a few extras onto a new AT4X.
As far as factory extras go, I would tack on the AT4 high clearance step ($1,095) and maybe some extra cargo tie-downs ($110). I likely also would splurge on a paint color other than white ($495).
As for third-party items, I definitely would go for a Roll-N-Lock Short Bed Retractable Tonneau Cover ($1,449) or a Putco VentureTEC Rack ($1,989) paired with a Rev Hard Rolling Tonneau Cover ($1,079) for a rooftop tent setup. While not critical additions, a Tuffy Under Rear Seat Lockbox ($579) and a Dometic CFX3-100 ($1,399) powered cooler would be worthy purchases. The storage unit would be perfect for securing firearms out of sight, and the cooler is an ideal solution for packing food into camp or meat out. If you’ have the cash for this brand-new off-road beast, then check out GMC’s Build and Price webpage to get rolling.