Originally Posted by MADDOG
What I found was that a wider tire kills mileage, not taller ones. I went from a 325 section width tire to a 285 section width tire and saw some gains from that. Also, I went to a forged aluminum wheel vs. a cast aluminum wheel and I'm sure that helped as well. Of course, the new tires were also a bit lighter but not much. Maybe 5 pounds per corner.
As far as how much, heck if I know. I had a lot of mods going on, intake/exhaust/programmer at the time and they all contribute.
I'd go with a narrow tire when it comes time to swap out.
I'd leave the gears alone for now.
Yeah I totally agree on the wider...wider equals more friction. The guy who had the truck before me swapped out the rims and they are a full metal rim so they are heavy and then on top of that went with 305 or 325 instead of the 285...can't remember.... But that was my thoughts go taller and back to stock width and then use the programmer to correct my speedo. But it just sucks that at 70+ I can draft and can't get nothing for mileage.