You'll get different MPG figures for:
* Engine size: A smaller engine will generally get better gas mileage than a larger one.
* Drivetrain: 4WD typically gets slightly lower MPG than 2WD.
* Cab size and bed length: Heavier configurations generally get worse gas mileage.
* Driving habits: Aggressive driving significantly reduces fuel economy.
To find the MPG for a *specific* Chevy Silverado, you should:
* Check the EPA fuel economy estimates: The EPA provides official estimates for each model year and configuration. You can find this information on the EPA's website (fueleconomy.gov) or on the Chevrolet website. Search for the specific year, engine, and trim level of the Silverado you're interested in.
* Look at owner reviews: Websites like Edmunds, Kelley Blue Book, and Consumer Reports often include owner-reported fuel economy figures. Keep in mind that these can vary widely depending on individual driving styles.
In short, you need to be much more specific about the Silverado you're asking about to get a meaningful answer.