So I was thinkin the other day. I currently have a 99 Runner with 265/70's and 4:30 gears. I had a 98 Runner previously with 265/70's and 4:10's. I got better mileage with the 98 than my 99.
So I'm thinkin that my 4:30's aren't as good a match for the 265/70's. Would I get better mileage with 265/75's?
I've searched, but haven't really found a good answer.
Thanks in advance.

 

It depends on what you're going after. If you're more concerned with the gas saving aspect, smaller tires will always win the war. If its just comfort then yes a 265/75 would be best, even a moderate 285 would be well suited.

 

hey benny if your interested in 4.56's let me know, i am trying to sell mine to go up to 4.88's

even though it might not help you in mpg

with the bigger tire your cruising rpm will be a little lower, with me when i had 265/70's my mph was a little off with 265/75 it was dead on and with 255/85 i am about 2mph slow

 

In regard to mileage, yeah you might benefit going up a tire size. But don't forget you will also add more weight. The 4.10 gears allow the rpms to run slightly lower than the 4.30's at the same speed with the same size tire. If you increase the tire size and not the gear ratio, then the rpms will be less with the bigger tire size, possibly increasing your mpgs.

 

That was my train of thought exactly. I did consider the added weight, but the size is not much bigger, so it wouldn't be much weight difference (in theory).

Here's what I've came up with over the last two days. I'd possibly gain hwy miles, but city miles would probably be lost.