I have a 2005 Silverado with a 6.0 with 35 inch tires and I'm getting 9 miles per gallon I was wondering what other people with the same setup I have done to increase miles per gallon? I'm thinking of doing a cai, throttle body spacer, tonneau cover and possible a tuner. Thanks

 

I've got a 01 5.3 on 8" of lift and 35s with upgraded gears from 3.73s to 4.88s, Longtube headers, intake, exhaust, and a custom tune. With the headers, intake, exhaust, and tune I was averaging around 13 and after the gear swap I'm at 13 too. It was just for better Driveability. Holds the gears better, pulls better, that sort of thing. But I'd do a airaid MIT kit and filter, exhaust, and a custom tune. Throttle body spacers are good paper weights, tuners don't do jack except extend shift points unless you have a diesel, and tonneau covers help, but not very noticeably

 

the throttle body spacer is a joke. get rid of it. use it as a paper weight. does not work at all with fuel injection. also, in my opinion, the hard cover does nothing but add looks to the truck. the truck aerodynamics was designed for the truck bed to be open and the tail gate up. this traps a cushion of air in the bed and that applies down force to the rear wheels giving the truck grip. also the airflow, after the cushion is formed, flows over the cushion and out the rear of the truck in a smooth flow. find a video on youtube. it will show this. the hard cover just upsets the air coming off the truck. unless you put a big spoiler on the back it will not help gas mileage. a good tune and exhaust and intake upgrade works best. also keeping the foot off of it helps too!!