i have a regular cab 8 foot bed and with the tail gate up i get 16 city and 18 highway but with the tailgate off or down i get 18 city and 23 highway i also have 3.08 gears in the rear and im running 235/75/15 tires. i invested in a k&n air filter which helped out and i have a glasspack exhaust that inproved my mpg.
10-14 mpg is what my silverado gets
19 hwy 15.5 city
Go to www.fueleconomy.gov
About 12 MPG. HWY. 10 in town
My 2005 silverado crew cab /6.0 averages 15.2 mpg
My 1998 C2500 gets 13-16 mpg.
I get about 14-16 mpg on my 1999 Chevy Silverado 1500, 5.3L V8
A 2007 Chevrolet Silverado 1500 gas tank holds 26 gallons of gas. The 1500 gets 14 mpg in the city, and 18 mpg on the highway.
If it has a 305 around 15mpg If it has a 350 13-14
12 to 13 MPG HWY. and 10 or so miles per gallon in the city.
Expect to get around 15 mpg in mixed driving and around 19 highway.
www.fueleconomy.gov 15 MPG city 20 MPG hwy