2024 6.6 Duramax Fuel Mileage. View detailed gas mileage data for the 2024 gmc sierra 2500hd. Therefore, to get better fuel mileage in a 6.6 duramax is by getting a new fuel filter, upgrading air intakes, tuning for extra mpg, load reduction, not leaving your.

2024 gmc sierra 2500 hd mpg. Use our handy tool to get estimated annual fuel costs based on your driving habits.