best tire size for 308 gears

[imdawrlus]

specifically what tire size would be the best size for gas mileage??? it has a 4.3 auto rear end gears are 3.08....might be getting new tires soon and performance isnt as big an issue vs gas mileage.....right now the tire size on the back is 31 inches......sometimes on the highway it feels like it cant get out of its own way...i was thinking 235 70's would be good.....THANKS!

[OBI WAN]

OK, for rough guessing.
Every inch changes the final drive by .17.
Smaller diameter tires turn more revs per mile than larger ones which will take mileage down some.
237/70/15's are what I run and work well with the 3.42's I have.
On yours the difference of a little over 2 inches would make it accelerate like a set of 3.42's and drop the mileage about .5-.75 MPG's but make it accelerate a little better. It may make no difference in mileage cause it can get it going a tad easier cause of the regear. This is very questionable how its going to work with a 3.08.If it was like 3.73+ then you would really notice a more measureable difference in mileage!

[mattownsa97withmafproblem]

yeah i need to find out what will work with my rear end i went to some pretty beefy 235's on the rear of my sonoma and the accelecration seems to have been affected i wanna go wider and the tire height lower profile so i can get better get up and go so any help would be appreciated

[mattownsa97withmafproblem]

oh and yes i have 3:08's on my truck has well it's an auto

[imdawrlus]

so if the tire size is so big that its bogging down, will that bring down mileage?? the tires i was looking at were about 28-29'' compared to 31....their also about half the weight.....i can imagine the change bringing up mileage a bit....but i guess my question is.....if i'm running at a higher rpm, will that bring down mileage even if the current setup is bogging down?? anyone want to take a shot at a *specific* tire size that would *generaly* be best??

[j894]

dont get 235 75s if you have 3.08 on an auto..
they suck for the most part acceleration wise, unless
your constantly at 70+ mph get somethingt smaller
(i have that combo thats what I run now)