The GMC Sierra AT4X Review

The GMC Sierra AT4X is one of the latest versions of GMC’s full-size workhouse pickup truck. It’s as “at home” on the ranch as it is at the country club and features just enough glitz to prove it. Napleton News had a chance to check out “the General’s” latest, this time as the off-roading-equipped Sierra AT4X. Buckle in, thrill seekers and let’s go for a ride.

What’s all this GMC Sierra AT4X stuff about?

The full-size truck market is chock-full of a bunch of great competitors ranging from the RAM, the F-150, Silverado and more. That’s why GMC is at the top of their game with the new Sierra AT4X.

The Sierra lineup takes advantage of four different engine choices. The base engine is a 2.7-liter turbocharged inline 4-cylinder engine delivering 310 horsepower and 430 lb-ft of torque. Next up is a 5.3-liter V8 engine with 355 horsepower and 383 lb-ft. A 3.0-liter inline-6 turbocharged diesel engine making 277 horsepower and 460 lb-ft of torque is third, while our AT4X was equipped with a 420 horsepower 6.2-liter V8 kicking out 460 lb-ft of torque.

Transmissions and drive configurations.

The base 2.7-liter engine uses an 8-speed automatic transmission. All others use a 10-speed automatic. Rear-wheel drive is standard, with four-wheel drive available throughout the lineup. But there are exceptions to this rule: All AT4 and Denali models are equipped with 4WD, as are any other Sierra powered by the 6.2-liter V8. Confused yet? It’s not that difficult to figure out.

The AT4X includes a 2-speed transfer case with selectable drive modes when venturing off-road. Underneath, there are front and rear e-locking differentials that vary the torque distribution of the truck. There are underbody skid plates and large steel transfer skid plate to dampen the effects of the unruly terrain the AT4X is likely to encounter.

Off-roading kit.

Multimatic DSSV shocks and dampers deliver premium performance and a two-inch lift. They add comfort whether on or off-road, thanks to increased suspension that softens the ride regardless of where you have traveled.

If there were another piece of kit that had us annoyed rather than pleased, it would be lack of side steps. Instead, American Expedition Vehicles have added a pair of rocker panel protectors to each side of the Sierra At4X. A couple of things are in play here: The AT4X rides two inches taller than the standard Sierra and Denali models. Those expecting the rocker panel protectors to act as steps to help overcome the taller ride height may find it a bit unsteady when using the protectors to climb aboard. After all, we prefer the auto-retracting steps, like those found on a Sierra Denali because, we think after dropping almost $90-large for a vehicle, you’re not going to subject the rocker panels to damage in the first place.

How does the AT4X look?

Blazing a new trail in first-class luxury. Those are the buzzwords GMC tosses about when discussing the new GMC Sierra AT4X. The first point is new badging to reflect AT4X vs AT4 trim levels. There are new 18-inch gloss black aluminum alloy wheels and dark nickel accents on the grille.

The Sierra Crew Cab is one of the nicest in the business and reflect the prestige that GMC brings to all its large trucks. The AT4X’s imposing looks make a statement as you drive up to your destination. We like the clever MultiPro tailgate, which offers a variety of positions that convert it from a tailgate to a bench, load steps and even a work desk.

How about inside the Sierra AT4X?

The biggest part of the interior improvements on the Sierra AT4X start with a new 13.4-inch infotainment touchscreen display. There’s heated and ventilated seating, Bose premium audio system, a digital gauge cluster and our favorite, massaging driver’s and passenger front row seating.

The second row is complete with comfortable bench seating that flips up to reveal more storage that help to keep things out of sight. Legroom in the second row is almost limousine-like.

Behind the wheel of the GMC Sierra AT4X.

Once you climb inside, it’s easy to feel at home inside the new Sierra AT4X. A press of the pushbutton starter is all that’s needed to get the party started here. Just look carefully for the button because at first glance, the button looks more like a parking brake release than the actual starter.

Power from the 6.2-liter V8 is plentiful and quickly available with the push of the skinny pedal. Road noise is almost non-existent as this Sierra veers towards the luxurious rather than the utilitarian.

Ride quality was also good and perhaps a bit floatier than you may even find in the Sierra Denali. We think it’s a result of the Multimatic DSSV shocks, which are tuned to jostling rides in much the same way the Ford Raptor takes advantage of its Fox shock absorbers.

Just bring a stepladder along for entry and exit from the AT4X.

GMC Sierra AT4X Specifications

	2023 GMC Sierra AT4X Specifications
Popular Powertrains
Engine Type	Gasoline powered 6.2-liter V8
Horsepower	420 horsepower
Torque	460 LB-FT
Transmission	10-speed automatic
Fuel Economy	24/22/27 (Combined/City/Hwy)
Suspension (F/R)	Independent/Solid Rear Axle
Turning Circle	46.9 feet
Also Available	Denali, short/long bed, trims
Specs
Warranty	3 years/36,000 miles
Powertrain Warranty	5 years/60,000 miles
NHTSA Safety Rating	4
Max Seating Capacity	5
Wheelbase	147.43 inches
Overall Length	231.72 inches
Width	81.24 inches
Height	75.51 inches
Cargo Capacity	Not Rated
Headroom, Front	43.03 inches
Headroom, Rear	40.12 inches
Legroom, Front	44.53 inches
Legroom, Rear	43.40 inches
Shoulder, Front	66.02 inches
Shoulder, Rear	65.16 inches
Towing Capacity	9,200 pounds