Mountain Wheels: Off-road ready GMC Sierra AT4X is geared for the trail

GMC’s upgraded Sierra 1500 AT4X adds serious off-road tools including locking differentials, skid plates and adjustable dampers.
Andy Stonehouse/Mountain Wheels

The boisterous and ungainly wall of metal that is today’s contemporary pickup truck is fine when parked at a gym or used to menace other drivers on the highway, but what happens when you hit real dirt?

I got an entirely different appreciation for the very impressive and imposing 2022 GMC Sierra 1500’s AT4X off-road edition by going off into the woods and sloshing through deep bodies of water, climbing steep, loose slopes and generally having a great time.

The race-worthy suspension with a two-inch lift kit and electronic spool-valve dampers, the oversized mud tires and rock rails all made a lot more sense when put to use doing challenging off-road stuff. It also has a full skid plate under the transfer case and has over 11 inches of clearance.

The net result was a much more satisfying experience in the $76,790 truck — yes, a gigantic pile of cash — and clearly getting your big GMC dirty, wet and dusty is a lot more fun than showing off in town.

I took the Sierra AT4X up above Central City and did all of the above, seeing how well its rather comprehensive off-road tools work, and how easy they were to access.

A three-mode terrain system, sort of hidden in the left-hand trailer control knob, allows both standard 4×4 and more sharpened rock-crawling settings, including a one-pedal accel-deaccel option for really precise throttle work over precarious surfaces.

The two-way lockable differentials are specific to this higher-than-AT4 model and make it much more like a Jeep Wrangler than a standard pickup. An adjustable hill-descent control rounds out the controls, helping when traction and climbing/downhill grip are critical off the highway.

Other niceties include an absolutely gigantic color heads-up display that will let you know the full pitch, yaw and degrees of steepness you’re achieving — kind of looking like a “Star Wars” laser-sighting system in the process.

The off-road mode also kicks in the front-view camera system, allowing you to more carefully crest hills and work your way around trail obstacles. It still a hell of a big truck and you will certainly have to be careful on narrow trails, or be ready to do some serious pull-offs to let other Jeeps and quads pass you.

I also appreciated the oversized Goodyear Wrangler DuraTracs on 18-inch aluminum wheels, which were not actually so bad on the highway, though certainly loud at times. The GMC’s suspension system does an admirable job of evening out the on-pavement experience, and I got almost no bounce or wobble, except maybe on some bad concrete sections.

Power here is a 6.2-liter Ecotec3 V-8 putting out 420 horsepower and 460 pound-feet of torque. GMC’s website suggests the regular AT4 may be able to get 26 highway mpg, but AT4X was definitely topping out at about 18, and was running in the indicated single digits as I headed up highway hills. It is certainly not short on power, or solid-sounding exhaust. Variations of the Sierra 1500 family can tow as much as 13,000 pounds of trailer and you’ll find digital assistance controls to help with that.

I also appreciated the MultiPro tailgate system, which can flip, flop and fold six different ways as a bench, step or bed extension, and also features a Kicker stereo system for your campfire rock-out sessions. As an aid to less spry individuals like myself, there’s now a helpful fold-down grab bar in the cab to help you climb up into the very tall box.

Inside, GMC has equaled the tech appeal of the Europeans by adding built-in Google Maps and operating system in its 13.4-inch navigation displays, which I found quite useful; the instruments are also digitized.

It’s certainly a beautiful truck inside, as well, with stitched leather everywhere, real wood accents and a classy and functional design. I very much like the easy-to-whack start/stop tab on the center stack, versus a regular button. An alternate power option, which I tried out a couple of years ago, is the 3.0-liter Duramax turbo diesel — the source of that higher highway mileage figure — that will also provide 460 pound-feet of torque and tow up to 8,800 pounds. Both engines are mated to a very adaptable 10-speed transmission.

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