The rugged 2024 GMC Sierra AT4X has an expanded powertrain lineup by being available with the recently updated Duramax 3.0-liter inline-six turbodiesel engine. These trucks begin arriving in showrooms in the summer. Pricing is not currently available.
The six-cylinder Duramax produces 305 horsepower and 495 pound-feet of torque. The only gearbox available with this engine in the AT4X is a 10-speed automatic. Motor1.com reached out to GMC to confirm whether the 420-hp 6.2-liter V8 would still be available for this trim of the truck. “Yes. The 3.0L will be the standard engine, though, similar to AT4,” a spokesperson told us.
The updated inline-six Duramax engine debuted last year and is available on some trims of the Chevrolet Silverado 1500 and GMC Sierra 1500. “Since the launch of the refined Duramax for the 2023 model year, around 20 percent of all Sierra 1500s sold have come with the engine and we expect its addition to the AT4X trim to take mix even higher,” said GMC Sierra Marketing Manager Will Mellon in this announcement.
The revisions to the engine included new pistons with a tweaked combustion bowl, revised turbo compressor, new fuel injectors, and improved temperature control features. Before these upgrades, the six-cylinder Duramax made 277 hp and 460 lb-ft.
The 2024 Sierra 1500 will receive some additional small tweaks. The Denali, Denali Ultimate, AT4, and AT4X will have new, power-retractable side steps. The Denali, Denali Ultimate, AT4, AT4X, and SLT will be available with an active exhaust. There will be two new wheel designs and two additional colors: Downpour Metallic and Thunderstorm Gray.
The available 2.7-liter turbocharged four-cylinder will now have the branding of TurboMax. The powerplant doesn’t change and continues to make 310 hp and 430 lb-ft. Buyers of the Sierra 1500 Elevation, SLE, and Pro trim levels can get this engine.
The Sierra 1500 AT4X trim debuted for the 2022 model year as a more rugged version of the truck than the AT4. The truck gets Multilmatic DSSV dampers. Compared to the AT4, the AT4X has an additional 2.0 inches of wheel travel in the front and 1.0 inch at the back. Underneath, there’s a larger skid plate protecting the transfer case. The truck rides on 18-inch wheels with 32-inch Goodyear Wrangler DuraTrac Mud-Terrain tires.
GMC is preparing to electrify the Sierra. The EV is also getting an off-road-oriented AT4 trim. The Denali EV Edition 1 is the first trim to arrive on the market in early 2024.
For more AT4X discussion, check out this episode of Motor1.com’s Test Car Happy Hour.
