The off-road focused 2024 GMC Sierra 1500 AT4X will get the 3.0-liter LZO Duramax diesel as the standard engine choice. Initially introduced on select trims, the LZO Duramax diesel is now the base engine for the AT4X trim with the 6.2-liter V-8 as the up-level engine choice.
For many U.S. buyers, diesel isn’t a well-known powertrain and that’s a shame. The refined second-generation 3.0-liter Duramax diesel has the dual benefit of good fuel economy and better low-end torque for towing and off-road driving.
The updated diesel is mated a 10-speed automatic transmission and produces 305 horsepower and 495 pound-feet of torque at just 2,750 RPMs. This means you get max torque much faster than most engines.
Fuel economy is better with 21/23 MPG city/highway versus 14/17 MPG city/highway (Duramax vs 6.2L V8) in the 2023 GMC Sierra AT4 trim. GM hasn’t officially revealed the AT4X fuel economy estimates, but I’d wager they are going to be the same or slightly less with the AT4X’s additional weight and equipment.
The con on the engine is diesel fuel is more expensive at the moment, and oil changes can be more expensive. Plus there’s the concern over dropping the transmission at 200,000 miles to inspect or replace an oil pump belt. However, owners like myself with our long-term Silverado with the LZ0 Duramax find real-world fuel economy is much better with the diesel. The quiet operation and smooth power delivery also make up for the extra fuel and maintenance costs.
GMC Sierra customers seem to be liking the engine as well.
“The 3.0L Duramax Turbo-Diesel engine has long been a favorite of Sierra light duty owners,” said Will Mellon, marketing manager, 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 up level 6.2-liter V-8 is impressive as well, yet the premium fuel required to achieve peak horsepower and torque has always been a bit of a bummer. It is also a $1,500 upcharge over the Duramax diesel — at least in the AT4 trim. No pricing yet for the AT4X but I’d expect a similar price difference.
While the diesel AT4X is the big news, and a good hunting rig, there are more changes coming for the 2024 model year.
These changes include:
The available active exhaust is the same change they did for the 2024 Chevy Silverado 1500.
When it comes to off-roading, towing and long distance driving fuel economy, it is hard to beat a diesel. This little 3.0-liter inline 6 has proven to be one of the best GM powertrains in years.