2025 Gmc 2025 Hd Denali Ultimate Dually Specs. The 2025 gmc sierra hd denali ultimate, refreshed for the 2025 model year, is gmc's most premium, luxurious and technologically advanced truck yet. Gmc released their all new 2025 gmc sierra 3500hd in early 2023, showcasing a number of new features and much needed improvements.
Denali ultimate hd trucks feature a standard powertrain upgrade, receiving the powerful 6.6l v8 l5p duramax diesel engine. The 2025 gmc sierra ev denali edition 1.