The most extreme version of the Sierra 1500, the off-road-capable AT4X trim, will now be offered with a fuel-sipping 3.0-liter Duramax diesel engine. The torquey unit will come as standard on the 2024 model year version of the truck.

The engine in question is the second-generation 3.0-liter Duramax, which in 2023 is only offered on select Sierra 1500 trim levels. The updated, second-generation diesel engine delivers more power and torque as a result of a variety of subtle improvements.

Thanks to new steel pistons with a revised combustion bowl, a retuned turbo compressor, new fuel injectors, and improved temperature control features, the engine now makes 305 hp (227 kW/309 PS) and 495 lb-ft (671 Nm) of torque. That’s 10 and seven percent more, respectively, than the first-generation engine could manage.

Read: 2022 GMC Sierra AT4X Offers Glamping For Off-Road Enthusiasts

 2024 GMC Sierra 1500 AT4X Gets More Powerful Duramax Diesel I6 As Standard

“These refinements of the 3.0L Duramax Turbo-Diesel engine took an already awesome engine and made it even better for off-road applications,” said John Barta, GM assistant chief engineer for diesel engines. “The outstanding low-end torque combined with the smooth and quiet power of this diesel engine, make it ideal for customers requiring on-road capability for things like towing, as well as off-road adventures like long-distance overlanding.”

The 3.0-liter Duramax will continue to be built at GM’s Flint Engine Operation in Michigan and will start being available later this summer. Although the engine will be the standard option for the 2024 GMC Sierra 1500 AT4X, the gas-powered 6.2-liter V8 engine (previously the model’s only engine), will continue to be offered as an optional extra.

“The 3.0L Duramax Turbo-Diesel engine has long been a favorite of Sierra light duty owners,” said Will Mellon, marketing manager for the GMC Sierra. “Since the launch of the refined Duramax for the 2023 model year, around 20% of all Sierra 1500s sold have come with the engine and we expect its addition to the AT4X trim to take mix even higher.”

The off-road-ready Sierra 1500 AT4X will continue to be offered as standard with Multimatic DSSV dampers, front and rear e-locking differentials, and more. Updated pricing information for the 2024 model year is not yet available.

Elsewhere in the lineup, the 2.7-liter inline-four engine will be renamed the TurboMax engine in 2024. It makes 310 hp (231 kW/314 PS) and 430 lb-ft (583 Nm) of torque and can tow up to 9,500 lbs (4,309 kg). It will be offered on the GMC Sierra 1500 Elevation, SLE, and Pro trims.

 2024 GMC Sierra 1500 AT4X Gets More Powerful Duramax Diesel I6 As Standard