2026 GMC Sierra 2500 HD AT4 Vs. 2026 GMC Sierra 2500 HD Denali

2026 GMC Sierra 2500 HD AT4 Vs. 2026 GMC Sierra 2500 HD Denali

2026 GMC Sierra 2500 HD AT4

vs.

2026 GMC Sierra 2500 HD Denali
6.6L Duramax V8 gas

Standard Engine

6.6L Duramax V8 gas
21,190 pounds

Maximum Towing Capacity

20,000 pounds
3,524 pounds

Maximum Payload Capacity

3,812 pounds
10.1 inches (11.1 inches with AT4X)

Ground Clearance

10.4 inches
69.5–83.5 cubic feet

Cargo Space

69.5–83.5 cubic feet

Whether you need something to help you with job site visits around Houston or something to help you haul your boat or camper, you’ll be thoroughly impressed with the GMC Sierra 2500 HD. While its base-level trims are certainly impressive, the upper-level AT4 and Denali trims offer even more features and amenities. Which trim is better suited for you: the GMC Sierra 2500 HD AT4 or the Denali? Big Star Buick GMC compares both trims to help you decide!
After comparing the GMC Sierra 2500 HD AT4 and the GMC Sierra 2500 HD Denali, visit our dealership to take either model for a test drive.

GMC Sierra 2500 HD AT4 Vs. Denali: Performance

Both models come with the same standard and available engines, producing the same level of horsepower. The only noticeable differences between their performance capabilities are their towing and payload capacities. We’ve listed those differences below:

2026 GMC Sierra 2500 HD AT4

AT4:

  • Standard 401 hp-6.6L Duramax V8 gas engine
  • Available 470 hp-6.6L Duramax turbo-diesel V8 engine
  • Maximum towing capacity of up to 21,190 pounds
  • Maximum payload capacity of 3,524 pounds

AT4X:

  • Standard 401 hp-6.6L Duramax V8 gas engine
  • Available 470 hp-6.6L Duramax turbo-diesel V8 engine
  • Maximum towing capacity of up to 18,500 pounds
  • Maximum payload capacity of 3,304 pounds

2026 GMC Sierra 2500 HD Denali

Denali:

  • Standard 401 hp-6.6L Duramax V8 gas engine
  • Available 470 hp-6.6L Duramax turbo-diesel V8 engine
  • Maximum towing capacity of up to 20,000 pounds
  • Maximum payload capacity of 3,812 pounds

Denali Ultimate:

  • Standard 470 hp-6.6L Duramax turbo-diesel V8 engine
  • Maximum towing capacity of up to 20,000 pounds
  • Maximum payload capacity of 3,153 pounds

As you can see, the AT4 offers slightly higher towing capacity, while the Denali has slightly higher payload capacity. Either model offers more than enough power to help you get the job done around Channelview or anywhere.

Schedule a test drive of the GMC Sierra 2500 HD AT4 or the GMC Sierra 2500 HD Denali at our dealership!

GMC Sierra 2500 HD AT4 Vs. Denali: Dimensions

The dimensions of these truck models are nearly identical, and the only significant difference is that the AT4 has different ground clearance measurements than the Denali.

Take a closer look at their dimensions:

2026 GMC Sierra 2500 HD AT4

AT4:

  • Ground Clearance: 10.1 inches
  • Wheelbase: 159–172 inches
  • Length: 250.8–266.8 inches
  • Cargo Volume: 69.5–83.5 cubic feet

AT4X:

  • Ground Clearance: 11.6 inches
  • Wheelbase: 159 inches
  • Length: 250.8–252 inches
  • Cargo Volume: 69.5 cubic feet

2026 GMC Sierra 2500 HD Denali

Denali:

  • Ground Clearance: 10.4 inches
  • Wheelbase: 159–172 inches
  • Length: 250.8–266.8 inches
  • Cargo Volume: 69.5–83.5 cubic feet

Denali Ultimate:

  • Ground Clearance: 10.4 inches
  • Wheelbase: 159–172 inches
  • Length: 250.8–266.8 inches
  • Cargo Volume: 69.5–83.5 cubic feet

Compare the GMC Sierra 2500 HD AT4 and the GMC Sierra 2500 HD Denali in more detail at our dealership. We’re conveniently located in Baytown, and we’ll pair you with a GMC Sierra 2500 HD that has all the features you need!

Choose Your GMC Sierra 2500 HD At Big Star Buick GMC!

Which truck will you choose to drive around Crosby? We can’t make the decision for you, but we can certainly guide you toward the right option. See which one of our GMC Sierra 2500 HD AT4 or Denali models stands out to you. When you find your preferred truck model, be sure to ask us about our new vehicle specials.

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