Fuel Mileage On 2024 Duramax V6. According to the most recent fuel economy testing from car and driver, the diesel silverado 2500hd gets 18 mpg in the city and 21 mpg on the highway. All in all, as far as mpg goes, the duramax 6.6 diesel is decent.

More importantly, the silverado’s duramax engine balances its strength as a tow option with phenomenal fuel mileage that won’t be duplicated by anything other than a diesel. All in all, as far as mpg goes, the duramax 6.6 diesel is decent.