About two months ago I bought a 2009 Chevy Silverado with a 5.3 engine and 2 Wheel Dr. I don’t know my gear ratio but I can give the Vin if that helps. I am averaging around 10 mpg city and 14 mpg highway which is way off the estimate mpg for the vehicle. there are no mods to this vehicle. It is stock besides having some red coils (not msd) and aftermarket headers (however stock equivalent) as previous owner said the stock headers were giving him issues. Has 169,000 miles on it. The valve covers must have recently been done as they don’t leak. The truck is in generally good condition and not beat up like a lot of other trucks i saw before purchasing this. Before people start saying well if you want better gas mileage get a prius. I get that’s its a truck but the gas mileage is just awful. Anything i should look into to help it out? I checked the air filter and that was clean.

 

Got any codes? That is rotten fuel mileage.