Originally Posted by thepitchedlink
Hello. what's the biggest tire someone has run on a 91 or 21? i'm looking for more ground clearance ....Can you get a pair of 275/75/r15's in there?
The 275/75R15 is 70 millimetres wider (the "205" and "275" are width in millimetres). It is also quite a bit taller, because each sidewall is 75% of the width (so 70 mm * 75% * 2 larger in overall diameter... about 105 mm or 4.1").
An ST205/75R15 is about 27 inches in diameter:
- 205*0.75*2 mm + 15" = 689 mm or 27.1"
- actual 27.1 inches in overall diameter for a Maxxis M8008
A 275/75R15 would presumably not be an ST tire (that's not a normal ST size)
- 275*0.75*2 mm + 15" = 794 mm or 31.2"
- I didn't find any tire (of any type) in this size in a quick look
So about two inches more ground clearance... but you would need to have the same two inches of extra wheel well clearance all the way around the tire, plus 35 mm of space to use up on each side of the tire as well.
There are lots of common light truck tire sizes around 32 inches tall - normally used on full-sized pickup trucks - which would be a more reasonable width... but most are now on 16" and larger wheels.