I have a 2014 Silverado 1500 LTZ Z71 5.3 it has a 6' Pro comp Lift kit and 35' Toyo A/T's I bought it from the dealership with the lift kit and tires ( all Work done by 4 wheel drive parts in dallas Tx) the dealership told me I should be getting around 15-17 MPG when I bought the truck last November the best I have gotten is 14 and its only because I was running 55 MPH anything over that and it drops to 9-11 MPG is this normal to drop fuel mileage that much is their any upgrades anyone could suggest to improve this issue I love the truck but I might have to sell and buy a diesel and I would rather not any advise will help thanks

 

sell it and buy a diesel?? what's that going to cost you??

probably the best thing to do to improve your mileage would be remove the lift and bit tires and go back to stock - you have to remember that you bought it from a salesman.............