Since its introduction in 2022, the off-road-focused GMC Sierra 1500 AT4X has exclusively employed GM’s familiar 6.2-liter gasoline V-8. The AT4X model is now getting a welcomed powertrain addition ...

The 2024 GMC Sierra AT4X is getting an upgraded powerplant for the new model year. Where it once solely featured GM’s 6.2-liter V8 truck engine, it’s now set to offer Duramax diesel power as standard.

About two decades after the launch of the 6.6-liter Duramax V8, GM's 3.0-liter Duramax inline-six turbodiesel arrived in 2019 with a promise to deliver "outstanding fuel economy, great horsepower, and ...