I have an AF1 air intake and a flowmaster exhaust and get about 17.8 MPG.
I started to slow it down a little bit (rolling to stop signs and red lights taking my foot of the gas a little more) and was getting 18.5 to 19 mpg.
Then i for some reason started to drive with my tail gate down just 2 see what would happen ( I know mythbusters did a show on it but i wanted to try it out) i was getting about 19 - 20 mpg ( Thats all about 65% hyw driving )
i have tested it out over the past few months and it dose help.

You guys can say what you want about me, But i know it helped me with the mpgs!

 

why not just get a tonneau cover.....that gave the best fuel economy

 

Well my way was free

 

mythbusters had scientific proof that it lowered your gas mileage...it was minimal but it did, it was less than 1 mpg and the raised fuel eco with the tonneau cover was less than 1 mpg too....but added up it was a little more than 1 mpg difference. Your truck so you can do what you want, but if you are trying to save fuel, i figured I'd fill you in on the results of the follow up show they did for the people like you who sent letters in

 

I dont care what they said it all make sounds good but at the end of the day
im getting more mpg regardless of what other people say.
I avg out my mpg every time i get gas and i could notice a difference but everyone will have there own opinion

 

Driving with your tailgate down is illegal here in california, unless loaded of course(for you smart guys out there).

 

It seems like everything in California is illegal, except the stuff that should be.

 

California....the restriction state

 

LMAO.....that is how their plates should read

 

i wish i was still stationed in NC some times