2024 Gmc Sierra 2024 At4x Duramax Mpg. While the regular 4×4 sierra with the duramax diesel gets 24 mpg combined, the at4x is rated at 19 mpg combined. Use our handy tool to get estimated annual fuel costs based on your driving habits.

Shoppers are paying 1.7 % less than msrp. While it has less horsepower, the diesel’s.