2025 Sierra Denali Ultimate 0-60 Mpg. The gears move quickly and the. Detailed specs and features for the 2025 gmc sierra 2500hd diesel denali ultimate including dimensions, horsepower, engine, capacity, fuel economy, transmission, engine type, cylinders,.

The denali ultimate trim has expanded from the yukon and sierra 1500 into the 2500hd lineup. The 1/4 mile time for the 2025 gmc sierra 1500 is 13.9 seconds.