2025 6.6 Duramax Mpg

2025 6.6 Duramax Mpg. The duramax diesel engine and its insane torque is the best thing about this truck. Though chevy's and gmc's 6.6 liter 6600 duramax diesel remains one of the most popular engines around, how much mpg can it really average?

View detailed gas mileage data for the 2025 gmc sierra 2500hd. Though chevy’s and gmc’s 6.6 liter 6600 duramax diesel remains one of the most popular engines around, how much mpg can it really average?