2026 GMC Sierra EV AT4 Review: What the Gas Truck Buyer Needs to Know

The gas-powered GMC Sierra AT4 is a truck I know well. Body-on-frame construction with an independent front suspension and solid rear axle, a 6.2-liter V8 making 420 horsepower (or Duramax diesel), and a cabin that places it among the better interiors in a full-size pickup at any price. The AT4 trim arrived on the Sierra 1500 in 2019 — not old, but present on enough Texas roads that AT4 owners trust it based on experience rather than expectation. It hauls, it tows, it absorbs broken pavement without comment, and the powertrain never draws attention to itself. The V8 is simply there when you need it.

GMC is betting that a buyer who knows that truck — who’s driven it, owned one, trusted one — is ready to walk into a dealer and pay $90,000 or more for a version with a 205-kilowatt-hour battery pack in lieu of a V8 or Duramax engine. Some of what those buyers get is genuinely better. Some of it isn’t.

The Look

The Sierra EV AT4 is a good-looking truck, and its design fits what it is. The EV-specific front end replaces the gas-powered truck’s conventional grille with a forward-leaning fascia featuring a darkened panel that doesn’t pretend to vent anything. It reads as intentional rather than compensatory, and it works. The blacked-out AT4 trim, red recovery hooks, 35-inch tires, and two-inch lift all carry over, and the LED taillamps flanking the tailgate give the rear a visual weight the gas-powered truck doesn’t have.

But the gas-powered Sierra AT4 has something the EV doesn’t: a clean, elegant severity that comes from years of iterative refinement on a platform truck buyers already know. It looks exactly like a capable truck that has been made progressively better. The EV looks like a truck designed to signal that something different is under it. Both are right for what they are.

The Platform: What 800 Volts Actually Means

The gas-powered Sierra AT4 is a body-on-frame truck with an independent front suspension, solid rear axle, and a 6.2-liter V8 — a configuration that works because it has been built, tested, and corrected on enough Texas roads and job sites that the failure modes are well understood. When GMC set out to build the Sierra EV, they made a different choice than Ford made with the F-150 Lightning: GMC started from scratch. The Ultium platform, shared with the Silverado EV and Hummer EV, is not a modified version of the gas-powered truck’s bones. It’s a dedicated EV architecture, and the most consequential decision in it is the operating voltage.

The Ultium platform runs at 800 volts. That puts it alongside the Porsche Taycan and the Hyundai Ioniq 5 — vehicles designed from the outset to take advantage of what higher voltage makes possible. The power you push through a charging cable is the product of voltage and current, and heat is the enemy of both. To charge faster without damaging cables and connectors, you can increase the voltage or the current. Raising voltage is the more practical solution at high charge rates — more current means more heat in the cable and connector, which imposes physical limits on how fast you can charge before the hardware degrades.

Ford built the Lightning on a modified version of the F-150’s existing platform, which ran at 400 volts and supported up to 150 kW at a DC fast charger — an architecture limitation that contributed to Ford discontinuing the Lightning in late 2025. The Sierra EV AT4, with its purpose-built 800-volt architecture, can accept up to 350 kW. In practice, a Lightning owner at the same fast charger added roughly 54 miles in 10 minutes. The Sierra EV owner is adding 100.

The 205-kWh battery pack is, by a considerable margin, the largest in the electric truck segment. The Rivian R1T Max carries 140 kWh of usable capacity. Drawing on 205 kWh through the dual-motor e4WD system, the Sierra EV AT4 Max produces 725 horsepower and 775 lb-ft of torque, and GM estimates 478 miles of range on a full charge — a range figure that leads every electric pickup currently on sale.

The honest caveat is that the Sierra EV earns that number primarily through capacity rather than efficiency. The Rivian R1T Dual Motor Max is substantially more efficient per kilowatt-hour and can cover comparable daily distances with a smaller pack. The Sierra EV’s answer to the efficiency gap is capacity: bring enough energy on board that the rate at which you use it no longer matters for most trips.

Charging Architecture: Sierra EV vs. The Competition

The 205 kWh Battery Goes Both Ways

The same pack that gives the Sierra EV its range advantage also functions as a 10.2 kW generator when the truck is parked. Through the available PowerBase Pro system, the AT4 Max offers up to six 120V outlets and one 240V outlet split between the bed and the cab — enough to run a refrigerator, window AC unit, power tools, and lighting simultaneously. A central AC unit running continuously will draw the pack down in roughly 30 hours. A refrigerator and basic lighting will run for days. For job sites, camping, or tailgating, that’s straightforwardly useful.

For Texas specifically, it’s worth stating plainly: the Sierra EV supports Vehicle-to-Home operation. Activating it requires the GM Energy PowerShift Charger ($1,699) and V2H Enablement Kit — home hardware you purchase separately — but once set up, the truck can backfeed a home’s circuits and keep essentials running through a grid outage. ERCOT’s track record in winter storms and hurricane season is recent enough that most Houston-area buyers don’t need reminding what a multi-day outage costs. A gas generator capable of delivering 10.2 kW of continuous output costs $800 to $1,500, requires fuel you may not be able to obtain, and sits in a garage doing nothing for the other 364 days of the year. The Sierra EV is already in the driveway.

Four-Wheel Steering and CrabWalk

Four-wheel steering on a truck this size changes two things you notice immediately and one you notice after a week. At low speeds, the rear wheels steer opposite the front wheels, tightening the turning radius so this 19.5-foot-long truck fits into parking gaps and makes U-turns that a conventional rear axle won’t allow. On the highway, the rear wheels toe in with the fronts, which settles lane changes in a way that a truck with a fixed rear axle simply doesn’t — less correction, less drift, more planted.

CrabWalk points all four wheels in the same direction simultaneously, moving the truck diagonally. GM positions it as useful for tight trail lines and precise hitch alignments — and in controlled demonstrations, it is. In everyday ownership, the situations where you actually need diagonal movement rather than just tighter steering are narrower than the feature reel suggests. It works as advertised. Whether you’ll use it more than a handful of times a year depends entirely on what you do with the truck.

The MultiPro Midgate

The gas-powered Sierra AT4 is a crew cab with a standard bed — 5 feet 9 inches of usable load floor. If whatever you’re hauling is longer than that and you don’t have a trailer, you’ll either make two trips or rent something else. The Sierra EV AT4 with the available Midgate adds a third option: drop the rear seatback, and the load floor runs continuously from the bed through the cab for just under eleven feet, with one rear passenger still able to sit on the other side of the divider. A sheet of plywood, a kayak, anything in the eight-to-ten-foot range that has always required a workaround — the Midgate loads all of it in one trip without a trailer. That’s a capability no gas-powered Sierra offers at any trim level.

Super Cruise

Super Cruise is available on the gas-powered Sierra AT4 as well, so this isn’t an EV-exclusive advantage — but it’s worth addressing because it’s one of the strongest arguments for the Sierra platform in any powertrain. On compatible mapped highways, the system handles lane keeping and speed management using pre-mapped LiDAR road data and GPS positioning as the primary inputs — meaning it isn’t dependent on real-time camera interpretation of lane markings, unlike most competing systems. The attention-monitoring system watches your face with an infrared camera, not your hands on the wheel, so it knows whether you’re actually watching the road.

On the stretch of I-10 between Houston and San Antonio, Super Cruise stays engaged through construction transitions and shifting lane configurations that cause camera-dependent systems to hand back control.

Where the Gas Truck Still Wins

The Ride

The AT4’s fixed coil-spring suspension was calibrated for off-road use. On public roads, particularly the concrete-heavy highway network around Houston, that tuning introduces a rhythmic bounce over expansion joints and uneven pavement that the gas-powered AT4 doesn’t have. It’s not uncomfortable in any acute sense — a single drive won’t bother you. Over a week of daily commuting, it becomes a consistent presence you’re aware of rather than a truck that disappears beneath you. The Denali EV uses adaptive air ride suspension and rides measurably differently. If your truck will spend most of its time on paved roads, drive both before deciding the AT4 trim is the right choice.

The Interior

The gas-powered Sierra AT4’s interior — particularly in SLT and higher trim levels — is one of the better truck cabins available. Materials that feel appropriate for what you paid, a layout that makes sense without a learning curve, soft-touch surfaces on every panel you contact regularly, and stitching that holds up to the price tag.

The Sierra EV AT4’s interior at $90,000 is harder to defend by comparison. The screen is larger, the eTrunk front storage adds something the gas-powered truck cannot, and the flat floor gives the cabin an openness that works. But the material quality has a flatness to it that only becomes visible once you’ve been in the gas-powered version recently. The AT4 spec uses synthetic leather throughout, and at a price point where competitors offer real hides, you notice. It’s the kind of detail that reads as cost-cutting at a price point where it shouldn’t.

No Apple CarPlay or Android Auto

The gas-powered Sierra AT4 supports both CarPlay and Android Auto. The Sierra EV does not. GM’s infotainment runs Google Built-in natively, bypassing phone mirroring entirely — a business decision about owning the software relationship and enabling over-the-air updates that may well make sense for GM’s long-term strategy.

For the person sitting in the truck, what it means is that every time you want to play something from your phone, run your preferred navigation app, or interact with your digital life the way you do in every other vehicle you’ve owned, you’re working around the system instead of through it. The 16.8-inch screen is a good piece of hardware. None of that changes the transaction: you are getting less phone integration than the gas-powered truck at a significantly higher price.

The Fixed Glass Roof

The fixed panoramic glass roof is standard on the AT4 Max Range — the trim you’re reading about — and there is no option to delete it or cover it. In Houston from May through October, that is not a cosmetic issue. The cabin heats through the glass in the time it takes to load groceries into the bed, and the air conditioning spends the first several minutes of every drive fighting the solar load before it gets to the air you’re actually breathing. The glass has infrared and UV coatings, which help but don’t fully solve the problem. A power sunshade is standard on luxury sedans and costs half as much. On a truck sold in volume across Texas, Louisiana, and Florida, its absence is a real daily cost that compounds month after month.

The Passenger Side Mirror

The Sierra EV’s high beltline, combined with the geometry of the passenger-side mirror, produces a sightline that requires leaning slightly forward and left to use correctly. The adjustment itself is minor. The problem is what it does to your confidence in the maneuver — when you can’t verify a lane change or a tight reverse with a natural glance, you second-guess what the driver aids are already telling you. The gas-powered truck’s mirror placement doesn’t create that hesitation. This is a major shortcoming of the Sierra EV, in my opinion, especially at this price point.

What 8,800 Pounds Feels Like

The Ultium battery pack accounts for most of the Sierra EV AT4’s 8,800-pound curb weight — roughly 60 percent heavier than the gas-powered AT4 — and the dual-motor e4WD setup distributes that mass well enough that it doesn’t feel like a burden. The truck doesn’t wallow, doesn’t lean, and doesn’t feel slow to respond.

What the weight does is remove feedback. The gas-powered AT4 has a more direct mechanical relationship between what you ask for and what you feel; the EV is composed enough that it stops communicating. That’s either refinement or isolation, depending on whether you want a truck that disappears or one that reports back.

The SSL Verdict

The gas-powered Sierra AT4 has a track record. It has been on Texas roads long enough that the people who trust it do so based on accumulated experience — not spec sheets, not press drives, but years of the truck doing what it was supposed to do without asking for attention. The Sierra EV AT4 Max is asking you to extend that same trust to a platform you haven’t lived with, a powertrain with no equivalent history, and a feature set that diverges from the gas-powered truck in both directions.

In several areas, it earns that ask. The 800-volt Ultium architecture and 350 kW charging capability are real engineering advantages. The 478-mile GM-estimated range leads the segment by a margin that matters on long Texas drives. The Midgate is a genuine capability that the gas-powered truck cannot match at any trim level. Four-wheel steering and CrabWalk have no equivalent on the gas-powered platform. Super Cruise is the most capable hands-free highway system currently available on a truck.

But the gas-powered Sierra AT4 rides more comfortably on the roads most owners actually use, connects to your phone without restriction, offers a more premium cabin at a lower price, and doesn’t trap solar heat through a glass roof you can’t cover. Those aren’t minor inconveniences. The Sierra EV AT4 Max is a well-engineered truck that makes specific concessions the gas-powered version does not. Whether what it does better outweighs what it gives up depends on whether your week in a truck looks like what this one was built for.