2025 Gmc Sierra At4 Mpg. With its base engine, the 2025 sierra is rated at up to about 19 mpg in the city and 22 mpg on the highway. Use our handy tool to get estimated annual fuel costs based on your driving habits.

Edmunds also has gmc sierra 1500 pricing, mpg, specs, pictures, safety features, consumer reviews. Fuel economy of the 2025 gmc sierra.