Ok guys and girls, I know this has been talked about many times. I've looked and cant find the answer I'm looking for. Sooooo my truck is seeming low on the mpg side of things 14mpg is the best I am able to get and that's with just switching to a 33x11.5x20 tire combo. And before it was 37x12.5x20 and it was only 12mpg. I just had the tranny rebuilt it has a sunnex drum harden shaft HD clutches. Transgo shift kit ,And a 2300stall converter triple disc. Fully deleted 4" exhaust and 6" lift. I drive moderately not trying to break things. I'm thinking it could just be the tuning that's in it but I have no idea what it is. Any thoughts or good suggestions. Thanks