2027 GMC Sierra AT4 First Look: No Leather, No Dipstick, No Problem
Full-size trucks are king in Texas, and few places prove it like Dallas. The city is one of the largest markets in the country for the GMC Sierra. So it made sense for GMC to bring its next-generation lineup to the State Fair of Texas. That is where I got a close look at the 2027 GMC Sierra AT4, the brand’s more mainstream off-road pickup.
The AT4 sits below the hardcore AT4X, but it is no pushover. It gets a 2-inch lift, the new 5.7-liter V8, Super Cruise, and a completely redesigned cabin. Pricing starts at $73,495, including a $2,795 destination charge, according to our 2027 GMC Sierra 1500 specs and pricing breakdown. I have not driven it yet, so consider this a detailed walkaround rather than a full review.
Two New V8s Headline the 2027 GMC Sierra AT4
GMC gives Sierra buyers four engines for 2027. The base 2.7-liter TurboMax four-cylinder gets a better turbocharger and now makes 350 horsepower and 455 lb-ft of torque. Meanwhile, the 3.0-liter Duramax diesel essentially carries over with 305 horsepower and 495 lb-ft.
The real story is the pair of new V8s. A 5.7-liter V8 powers our AT4, while a new 6.6-liter V8 replaces the old 6.2-liter. General Motors invested $888 million in the plant that builds them, which shows how serious it is about eight cylinders. We dug into that investment in our story on GM’s new small-block V8 engines.
I talked with Scott Garver of GM about the new engines. He called the 5.7-liter “our workhorse” and said GM expects it to be the higher-volume engine. It makes 402 horsepower and 428 lb-ft of torque. Engineers squeezed out every bit they could, hence the oddly specific 428 measurement. In the Sierra, it tows up to 13,500 pounds when properly equipped, making it the towing champion of the lineup.
The 6.6-liter V8 is the power play, with 481 horsepower and 501 lb-ft. GM targets buyers who want performance without compromise. In the Sierra lineup, that means the Denali Ultimate and AT4X.
Both engines are clean-sheet designs, and both skip the traditional dipstick. Instead, an electronic oil level sensor sends a reading to the center screen or driver information center. As a result, you can check your oil in real time, even on a road trip. GM also nodded to history by stamping “350” on the 5.7-liter block and “400” on the 6.6-liter. When I asked Garver what he is most proud of, his answer was simple: “The torque.”
The AT4 Looks the Part Without Going Full AT4X
The 2027 GMC Sierra AT4 rides 2 inches higher than standard models, which also improves the approach angle. Red tow hooks are a must on any off-road truck, and here they are mounted vertically. The reworked bumper mixes plastic and metal, with metal skid plates tucked further underneath. It is not as aggressive as the AT4X, but it still looks ready for a dirt road.
Up front, the Sierra’s question mark lighting signature evolves again. The AT4 adds a blacked-out grille, a red GMC logo, and an AT4 badge. The wheel arch moldings now use sharper, geometric angles instead of a smooth radius.
Our truck wore two-tone 20-inch wheels with 275/65R20 Hankook Dynapro AT2 Xtreme all-terrain tires. I am told 18-inch wheels are standard, and personally, I would choose those.
GMC also moved the engine displacement badge to the hood, and the AT4 badges now sit low on the doors. I think both are more logical spots than the fender badges on the Chevrolet counterparts. On our white truck, black mirror caps and door handles add contrast.
Better yet, proximity entry works on all four doors, so you can unlock the rear doors without digging for the key fob. That matters on a hot Texas summer day.
A Greener, Smarter Cabin With a Secret Glove Box
The interior is vastly improved for 2027. Our AT4 paired black with a dark green on the doors and dash. It takes direct sunlight to really notice the green, but I love seeing color return to truck interiors. Unfortunately, there is still plenty of gloss black trim.
The driver’s door has two-person memory, express up and down front windows, and a single control panel for the mirrors and locks. The door pocket easily holds two water bottles and an umbrella. There is also a pass-through upper bin with a lip, so items will not roll out.
Leather is gone across the Sierra lineup, even on the Denali and Denali Ultimate. Instead, GMC uses a premium leather alternative, which is essentially marketing speak for a very high-end vinyl. It feels soft and smooth, with no graining, and GMC engineered it to wear better. Time will tell. We explained this change in our story on why the 2027 Silverado and Sierra have no leather seats.
The center console is where GMC gets clever. Moving the shifter to the steering column frees up room for a workstation that extends without a gear lever in the way. You also get two magnetic phone chargers, two USB-C ports, and a household-style outlet up front. The big console bin passes through to the front, and a sliding panel can hide a laptop. Rear passengers get two more USB-C ports. Overhead, a new panoramic sunroof lets in plenty of late-September Dallas sun.
The Tech Is Less Imposing Than Photos Suggest
Every 2027 Sierra gets a new digital gauge cluster and a 16.3-inch touchscreen. The base Pro borrows Chevrolet’s dash design, but the Elevation, AT4, Denali, AT4X, and Denali Ultimate get GMC’s own layout. It looked like a massive wall of screens in photos. In person, however, it is far less intrusive than I feared.
Our 2027 GMC Sierra AT4 also had a head-up display and illuminated buttons on the steering wheel for driver assistance features, including adaptive cruise control and Super Cruise. The new infotainment interface uses a high-contrast black-and-white design. Garage door openers now live on the screen as GPS-based shortcuts that pop up when you get close to home. Dual-zone climate control keeps redundant physical controls for temperature and fan speed, which I appreciate.
The home screen splits into a map and a customizable pane for vehicle status, trailering apps, and more. Apple CarPlay and Android Auto stay, too, as we reported when GM reversed course on CarPlay. Phone projection fills one side, and you can keep CarPlay audio controls in the other pane. It is a nifty solution.
The 11.5-inch passenger screen is heavily polarized, so I could not see it from the driver’s seat. That lets your co-pilot watch apps while the truck is moving. With its cover closed, a slim section displays the time, destination, and directions. Press another button, and the main screen motors out of the way to reveal a hidden second glove box with a rubberized mat. Below the screen, gloss black buttons handle climate, the two-speed transfer case with Auto, drive modes, and trailer brake controls.
Back Seat and Bed: Family Friendly, With a Fish Ruler
Rear proximity entry means I can walk straight to the back door and get Tucker settled into his car seat. The key fob carries over, and a couple of presses of remote start fires the truck right up. Our truck had no running boards, so a B-pillar grab handle helps you climb in. At 5 feet, 10 inches tall, I had plenty of room, even with the sunroof’s roller shade overhead.
The under-seat storage is easier to reach, with no latches or levers. You can flip the cushion up with one hand and nudge it back down. Heated outboard seats, air vents, and USB-C ports round things out. However, the rear seatback storage bins are gone. GM also still does not offer a fully flat load floor like Ford and Ram. The hump is barely noticeable, but it could matter if you use the back seat for cargo.
Out back, the MultiPro tailgate gets clearer buttons. A U-shaped button opens the full gate, and a bar-shaped button drops the inner gate. New D-rings rated at 250 pounds each add tie-down points, and the load stop now has tick marks for measuring your catch. You also get a spray-in bedliner, LED lighting, corner steps, and a heated, and a sliding power rear window.
Is the 2027 GMC Sierra AT4 the Right Trim for You?
I expect to see plenty of these on Texas roads. The 2027 GMC Sierra AT4 pairs real off-road style with the towing-champ 5.7-liter V8 and a cabin packed with smart storage and tech. It does not go as far as the AT4X, and at $73,495, it is not cheap. Still, it may be the right balance for families who want a truck that works during the week and plays on the weekend.
Chevrolet took a different approach with the same hardware, as our 2027 Chevrolet Silverado ZR2 first look shows. For now, I still need EPA fuel economy numbers and, more importantly, seat time. Until then, subscribe to the GT: Garage Talk® newsletter for the latest automotive news every week.