2027 GMC Sierra 1500 AT4 Pairs a Lift With a Luxury Cabin
The 2027 GMC Sierra 1500 AT4 occupies a particular spot in GMC’s new half-ton lineup. It gets a factory lift and 34-inch all-terrain tires, but also a panoramic sunroof, ventilated seats and hands-free driving assistance. Starting at $73,495 for a four-wheel-drive Crew Cab, including the $2,795 destination charge, it is neither the least expensive way into a Sierra nor the most aggressive off-road version. That distinction belongs to the AT4X.
A Squarer Face and a More Useful Bed
The redesigned Sierra wears a taller-looking grille, sharply defined bodywork and lighting that traces a seven-like shape at each corner. On the AT4, the dark front-end detailing and raised stance suit the truck better than extra brightwork would. It looks substantial, though the grille still takes up an awful lot of the view from the front. Welcome and departure lighting animations and an illuminated GMC signature are available in the broader lineup.
GMC has also revised the available MultiPro Tailgate with a measuring ruler, four additional tie-down points and a different exterior panel. The bed has 16 standard tie-down locations, separate from those added to the tailgate. GMC claims class-leading cargo volume but has not provided a volume figure here to put that claim in perspective.
Inside, the AT4 trades a purely utilitarian approach for heated and ventilated 12-way power front seats, dynamic ambient lighting and a standard panoramic sunroof. Its MultiPro center console adds storage and an extended work surface. GMC says the Crew Cab has class-leading standard front headroom and legroom. A utility wall, assist steps, a bed cover and an AT4 Premium accessory package offer further ways to configure the truck.
Two Engine Choices, One Clear Towing Caveat
The standard 2027 Sierra AT4 engine is a new 5.7-liter V8 producing 402 horsepower and 428 lb-ft of torque. An optional 3.0-liter Duramax turbo-diesel makes 305 horsepower and 495 lb-ft. Both use a 10-speed automatic transmission and, according to GMC’s specifications, a 3.23 axle ratio. The new V8 belongs to GM’s sixth-generation small-block family and uses both port and direct fuel injection, along with a higher compression ratio, a larger throttle body and a revised intake manifold.
A roughly 34-gallon fuel tank is optional on the AT4. With that tank, GMC estimates that a diesel Sierra can travel more than 900 highway miles, although EPA fuel-economy figures are not yet available. GMC has not published an AT4-specific 0-to-60-mph time or top speed.
The wider Sierra range puts those engines in context. Pro and Elevation start with an updated 2.7-liter TurboMax four-cylinder rated at 350 horsepower and 455 lb-ft, increases of 40 horsepower and 25 lb-ft. Its revisions include a new turbocharger, fuel-injection changes, updated thermal management and redesigned pistons. A new 6.6-liter V8 produces 481 horsepower and 501 lb-ft, but GMC reserves it for other trims, including the AT4X. All four engines pair with a 10-speed automatic.
GMC quotes a maximum 13,500-pound tow rating for a properly equipped 5.7-liter Sierra Double Cab with the Max Trailering Package. A similarly equipped four-wheel-drive Crew Cab tops out at 13,300 pounds, while a four-wheel-drive diesel Crew Cab with that package reaches 12,100 pounds. Those are configuration-specific Sierra ratings, not promises for an AT4 with its lifted suspension and off-road tires. Buyers who tow should check the rating of the exact truck they order.
Trail Hardware Without the AT4X Price
The GMC Sierra 1500 AT4 comes with a two-inch factory lift, monotube shocks and 34-inch all-terrain tires; 20-inch wheels are optional. It retains the Sierra’s independent front suspension and solid rear axle with leaf springs. That setup makes the AT4 a meaningful step away from a standard road-focused truck without turning it into the lineup’s most specialized trail machine.
The AT4X makes that distinction plain. Starting at $85,495, it adds 35-inch mud-terrain tires, Multimatic dampers with new jounce-control hardware, electronic locking front and rear differentials, and a Baja mode that changes throttle, transmission, damper and stability-control settings for fast travel over loose terrain. It starts with the diesel and offers the 6.6-liter V8. A later-arriving AT4X AEV Edition adds protective bumpers and skid plates, recovery hooks, black steps, beadlock-capable wheels and other AEV parts. The AT4 does not claim that level of equipment, and its $12,000 lower starting price reflects it.
Displays, Cameras and Hands-Free Towing
The AT4’s standard displays include a 16.3-inch center touchscreen and a 12.2-inch driver display, plus a head-up display. The number of screens are hard to ignore. GMC’s new interface combines a configurable home screen and 3D vehicle views with shortcuts for navigation, media, off-road information and trailer tasks. The driver display offers several layouts, including a Tow/Haul view.
Apple CarPlay and Android Auto work alongside the truck’s built-in Google services, which include Maps, Gemini voice features and access to apps. Over-the-air updates are supported. The optional Technology Package brings an 11.5-inch front-passenger entertainment screen with an articulating cover; a polarized display helps prevent its content from distracting the driver. Depending on equipment, the Sierra can also offer 5G connectivity, six USB ports, an HDMI connection, a 120-volt console outlet and two MagSafe wireless charging pads. The AT4 includes the dual charging pads and an eight-speaker Bose audio system with a Richbass woofer.
Available camera equipment supplies up to 19 views. Choices include Hitch View, a transparent-trailer perspective, Cabin Glance, a rear camera mirror and front and rear underbody cameras with washers. The in-vehicle Trailering App and mobile trailer-light checks address less glamorous but useful towing chores; a Trailer Brake Gain Assistant is also available. Underbody cameras are among the AT4’s options rather than standard equipment.
Super Cruise is standard on the AT4 and supports hands-free driving with a trailer on compatible roads. GMC includes three years of its OnStar One plan. Automatic and turn-signal-initiated lane changes are available when conditions permit, but neither works while trailering. Adaptive cruise control is standard, and the new interface lets the driver activate it or Super Cruise with one tap.
The standard safety list is extensive: intersection and reverse automatic emergency braking, front pedestrian and bicyclist braking, a side bicyclist alert, rear pedestrian alert, forward collision warning, blind-zone steering assistance, rear cross-traffic braking, front and rear parking sensors, automatic high beams, a Safety Alert Seat and an HD rearview camera. As with the hands-free system, these features assist an attentive driver rather than replace one.
Where the AT4 Fits
The 2027 Sierra lineup runs from the $51,295 Pro to the $87,895 Denali Ultimate. Elevation starts at $59,995, while the more road-oriented Denali starts at $76,795. All those prices, including the AT4’s $73,495 sticker, apply to four-wheel-drive Crew Cab models and include destination. Other cab, bed and package prices will differ, and GMC expects the first 2027 trucks at dealerships before the end of 2026.
The 2027 GMC Sierra 1500 AT4’s case rests on its combination of a standard V8, useful off-road hardware and a notably well-equipped cabin. The trade-off is straightforward: buyers pay considerably more than they would for an Elevation, while the AT4X remains the one with locking differentials and more serious trail equipment. The AT4 sits between them, with enough comfort features to make its rugged appearance feel like only part of the story.
