2026 GMC Sierra EV AT4 First Drive: Sprinkling More Adventurousness Over the Electric Sierra

GMC, itself one of General Motors' four main brands, has become host to a motley collection of sub-brands of its own. The luxurious Denali, created 25 years ago, has been a huge success as a top-tier trim across GMC's truck and SUV lineups. Denali-spec GMCs account for almost a third of retail sales and nets the largest profits. GMC, a brand that consists only of trucks and SUVs, also serves as the home for the resurrected Hummer sub-brand, which exists as an all-electric off-road outfit. Meanwhile, GMC is also seeing gains from another sub-brand, AT4, which was created seven years ago for the more adventurous buyer who spends time going off-road or at least dreaming of doing so.

The strategy continues in the EV era. The latest: the 2026 GMC Sierra EV is now available in the off-road AT4 trim and GMC thinks it will appeal to about 20 percent of Sierra EV buyers. AT4 is now available across the GMC line with the exception of the Hummer EV pickup and SUV, which are billed as super trucks both on and off-road already. Plus, crossing sub-brands would just get too complicated, right? Anyone pining for a GMC AT4 Denali Hummer?

The Sierra EV is in its third model year. It falls between more revolutionary electric trucks from Tesla and Rivian, and more conventional-looking ones from Ford (F-150 Lightning) and eventually Ram (the 1500 REV), both of which strongly resemble their internal-combustion-engine siblings. Where the Sierra stands out is range: the AT4’s 478 miles with the Max Range model. It can plug into 800-volt DC public fast chargers, gobbling juice up to 350 kW, enabling up to 100 miles of range accrual in approximately 10 minutes.

The other specs are similarly impressive. The EV's dual motors make it the most powerful Sierra model with 725 horsepower and 775 lb-ft of torque for a claimed 0-to-60 mph time of less than 4.5 seconds with the Max Range model. With the Extended Range you get 625 hp. And the Extended Range truck can tow up to 12,300 pounds.

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What Makes the 2026 Sierra EV AT4 More Off-Road-Ready?

The Sierra EV AT4 has an extra 2 inches of ground clearance over the base Elevation trim. The Denali splits the difference: it has air suspension, which can raise the truck a couple inches. But it still rides about an inch lower than the AT4 because the Denali has standard 24-inch wheels while the AT4 rides on 35-inch all-terrain tires on smaller rims.

We spent a day outside Detroit on the massive acreage of the Huntsman Hunt Club in Dryden, Michigan. The trails on the 900-acre private shooting preserve were not so tough that they tested the limits of the truck’s extra ground clearance, but we can appreciate how welcome it would be on a gnarlier trail or after a heavy snowfall. Especially given how a Sierra EV Denali we tested for Truck of the Year in 2024 often introduced its belly to obstacles during our off-road evaluations, the lift seems well worth it. And the truck glided over cones set out to mark our trail—that we drove over inadvertently—without tipping them.

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Love Four-Wheel Steering

Arguably the AT4's best feature is the four-wheel steering (also available on non-AT4 models). It gets the big truck out of tight situations. Our day wending through trails with sharp turns around trees highlighted this. The truck made turns easily in situations that would have been three- or five-point turns otherwise. It never got old. Rear-wheel steer provides the same amount of angle as other Sierra EVs; the difference is how quickly it gets there, with the AT4 delivering a much faster response.

Having rear steer also make it possible to offer party tricks like Crab Walk, the feature introduced on the Hummer where the front and rear wheel are turned in the same direction, allowing the vehicle to skittle diagonally like a crab. Four-wheel steering is standard on the AT4, optional on the Denali.

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Terrain Mode Unique to AT4

Like in other Sierra EV trim levels, there is an off-road mode to maintain traction when wheel slip is detected. It lowers slip at higher speeds. Unique to the AT4 is Terrain Mode for low-speed maneuverability, an overlanding mode made possible via software. Terrain Mode provides more aggressive brake control and works up to a speed of 25 mph. The friction brakes come in faster and more aggressively to get over an obstacle more smoothly. Think of it like cruise control for off-roading.

The course we took did not have any large logs or boulders to test the feature at its limits, but we got to play with it on some small hills for a taste of its control. It kept wheels from spinning, even in a patch of mud. The braking is aggressive and will bring the vehicle to a halt. And yes, GMC also offers one-pedal driving which also brings the vehicle to a complete stop. You have to go into the screen to turn it on but the setting remains when you turn the truck off and back on.

What Else Does the AT4 Have?

The AT4 has a coil-spring suspension which is bumpy and a bit harsh on a dirt trail. No question, the Denali with its air suspension is smoother, at least on-road, though you give up the AT4's beefier tires and are more likely to bash those pretty 24-inch wheels on rocks and such.

Like its internal combustion engine counterpart, the Sierra EV has GMC’s MultiPro midgate expandable bed that transforms a 5-foot, 10-inch bed to a 9-foot, 1-inch space with the midgate opened. Drop the tailgate, too, and you unlock a full 10-foot, 10-inch cargo platform.

We drove a black AT4 with a black interior. Compared with its engineering twin, the 2026 Chevrolet Silverado Trail Boss, the difference inside comes down to styling, material, and colors. Oh, and the cabin is quieter thanks to GMC’s use of acoustic glass.

The 16.8-inch infotainment screen, mounted on the dash with a vertical portrait orientation, is standard. Activate the cameras for a crystal-clear image of the trail below you. Also standard: heated and cooled front seats, heated rear seats, head-up display, spray-on bedliner, and Super Cruise hands-free driver assist.

How Much Does the 2026 Sierra EV AT4 Cost?

The Sierra EV Extended Range AT4 starts at $81,395; go for the bigger battery Max Range and it starts at $91,695. For comparison, the base Elevation trim starts at $64,095.

The AT4 is the utility lynchpin in the lineup with its combination of capability with its additional ground clearance, four-wheel steering, Terrain Mode, red front recovery hooks, expandable bed and exceptional EV range, making it the Swiss army knife of the portfolio. We wish it rode a little smoother in the rough stuff where it's designed to go, but remember—the Sierra EV is very, very heavy, and there are limits to what normal coil springs can handle. It seems air springs are being reserved for the Denali and the Hummer models, though the Hummers are the only ones to combine them with off-road tires. At least the chunky tires give you more confidence steering the AT4's nose toward those bumps, even if traveling over them will be bouncier and louder than in the Hummers.

The additional trim is expected to help GMC smash its U.S. sales record in 2024, says Patrick Finnegan, senior marketing manager for GMC trucks. That includes EVs which are up 183 percent compared with a year ago; helped by Hummer’s best quarter to date to start the year. The GM electric trucks combined (GMC and Chevy) sold about 9,560 through May, just shy of the Ford -150 Lightning at about 10,800, and the Tesla Cybertruck at almost 10,100, according to MotorIntelligence.

The AT4 family continues to grow business without cannibalizing on the other trim levels. It accounts for about 21 percent of total GMC sales, bringing in younger, higher-income buyers who tend to stay loyal to the brand, Finnegan says. Adding the AT4 should continue this trend.