The 2015 Chevrolet Silverado 2500HD Vortec, which takes gasoline, gets 10.3 average miles per gallon, according to Truck Trend Network. The 2015 Chevrolet Silverado 2500 HD Duramax, which takes diesel fuel, gets 15.3 average miles per gallon. The mileage information on both these vehicles pertains to eight-cylinder engines.
Fuel economy may vary on this vehicle depending on its specifications, such as whether the truck has a standard box or a long box and whether it has a regular cab or a crew cab. Fuel economy may also vary based upon the year of the truck. Fuelly reports that 2013 models of this vehicle get an overall average of 13.69 miles per gallon; 2011 models get an overall average of 15.73 miles per gallon; and 2009 models get an overall average of 12.78 miles per gallon.