2023 GMC Sierra 1500 Denali Ultimate Duramax Review - Delivering on a Promise

The General Motors truck line is very wide and also deep. It is wide in the sense that there are many different models and sizes. It is deep in the sense that within any given size, GM usually offers two brands, Chevrolet and GMC, and within each brand, there is a long list of trims and feature packages. We recently tested what can be considered the top of the heap for GM’s truck line. The 2023 GMC Sierra 1500 Denali Ultimate Duramax. What we have found is that GMC Denali delivers on its promise to be the best in a great line of trucks.

Related Story: 2023 Chevrolet Silverado ZR2 - What Makes It So Special?

2023 GMC Sierra 1500 Denali Ultimate Duramax - What Is It?
The GMC line is GM’s “Contractor Grade” or premium brand of trucks, with Chevrolet being the mainstream or sport truck division. There is overlap for certain, but GMC is generally the choice for those who want more luxury items and a more premium look and feel. 1500 means it is the base truck in terms of strength and capacity. Denali is GMC’s way of signaling a high trim level. Ultimate means a high-content package within the Denali trim line. Durmax refers to the optional diesel engine.

2023 GMC Sierra 1500 Denali Ultimate Duramax - What Makes It Special?
The Duramax engine is the biggest specialty feature of the truck we tested. Diesel engines offer two main advantages. First, torque for towing. Second, fuel efficiency (but not economy). In our back-to-back testing of a Chevy Silverado with the 6.2-Liter gas engine and the Duramax diesel, we saw a fuel efficiency of about 16 MPG for the gasser and about 24 MPG for the oil burner. This sounds great until you pull up to a gas station and see that diesel costs 50% more than regular unleaded.

The interior is a bit fancier than what we found in a more expensive Silverado we recently tested, but basically the same construction.

The 2023 GMC Sierra 1500 Denali Ultimate Duramax also has extending running boards to help you climb in. My wife loved them. I don’t. I prefer fixed steps if any.

The tires are not mud-whompers, but rather touring tires with low profiles. These would seem to help with handling and road noise.

GM’s outstanding infotainment system is the same in the GMC line as in the Chevy line. Still, it is the best in the business. Wireless Apple Car Play and Android Auto with no subscription needed.

GM’s corner step helps you enter the truck bed safely.

GM’s multi-function tailgate is on hand to perform party tricks.

The rear seats offer heating and there is a handy USB port for the folks in the back seats.

2023 GMC Sierra 1500 Denali Ultimate Duramax - How Does It Drive?
We found the Sierra Denali Ultimate to be a great everyday driver. It is peppy, smooth over bad bumps, and handles pretty tightly. Much better than you would assume if you don't drive modern trucks on a regular basis. The Duramax is not a negative but not a positive in normal driving. We preferred the 6.2-liter gas engine. If you tow, you already know the upside.

The feature we liked best was the downhill assist. Perfect for slippery slopes.

2023 GMC Sierra 1500 Denali Ultimate Duramax - How Much Does It Cost?
Our test truck had a price including destination fee of $81,355. The Duramax engine actually deducts $1,500 from the cost.

2023 GMC Sierra 1500 Denali Ultimate Duramax - Conclusion
If you are shopping for a new truck, the chances are you already know which manufacturer you are going to buy (Ford, Ram, GM, Toyota, or Nissan). GMC is the one to pick if you are in the GM champ and want a luxury truck. Based on our testing, we feel it is a wise choice.

Image. of 2023 GMC Sierra 1500 Denali Ultimate Duramax by John Goreham.

John Goreham is an experienced New England Motor Press Association member and expert vehicle tester. John completed an engineering program with a focus on electric vehicles, followed by two decades of work in high-tech, biopharma, and the automotive supply chain before becoming a news contributor. In addition to his ten years of work at Torque News, John has published thousands of articles and reviews at American news outlets. He is known for offering unfiltered opinions on vehicle topics. You can follow John on Twitter, and TikTok @ToknCars, and view his credentials at Linkedin