i have two choices on tires for my rims and was orginally going 335, then switched to 315 but i was just running the numbers and what originally looked fine now does not

Front:
285/30/22 diam: 28.73" Circ: 90.27"

Rear:
315/25/22 diam: 28.20" Circ: 88.60" (1.67" difference)
335/25/22 diam: 28.59" Circ: 89.83" (0.44" difference)

so 1.67 seems lke way to much, what is the allowable difference?

Why not just go with the 275/315 set up like a lot here have done with good results.
I think the 285/335 set up will be to big.
Maybe some of the so-called experts here will chime in with more info.

i have two choices on tires for my rims and was orginally going 335, then switched to 315 but i was just running the numbers and what originally looked fine now does not

Front:
285/30/22 diam: 28.73" Circ: 90.27"

Rear:
315/25/22 diam: 28.20" Circ: 88.60" (1.67" difference)
335/25/22 diam: 28.59" Circ: 89.83" (0.44" difference)

so 1.67 seems lke way to much, what is the allowable difference?

The difference can be + or - 3% but that doesn't mean you wont have transfer case issues. The closer you can stay to 0% the better. You need to check your calculations and change that to a % not inches. http://www.miata.net/garage/tirecalc.html

You need to stay VERY close to the same rolling radius or your transfer case will fail.
Here is a very simple test:
Put a piece of tape on each tire, vertically from the rim to about an inch from the ground.
Slowly roll the Jeep so you have made 5 full revolutions.
The 4 pieces of tape should be in the same place on each tire after 5 revolutions.
BBill

The difference can be + or - 3% but that doesn't mean you wont have transfer case issues. The closer you can stay to 0% the better. You need to check your calculations and change that to a % not inches. http://www.miata.net/garage/tirecalc.html

+1. Keep it tight as possible.

25 or 30 series tires? don't hit any pot holes...

25 or 30 series tires? don't hit any pot holes...

I had 275/25/24's on my 300c SRT8....decent sized potholes didn't hurt em'....


A deep enough pothole will hurt ANY rim not just low profile

really? A guy here at work has 35s on his R32 and he's constantly bending rims. Honeslt he's the only one I know (well other than you now, haha) that has that low of a profile.

really? A guy here at work has 35s on his R32 and he's constantly bending rims. Honeslt he's the only one I know (well other than you now, haha) that has that low of a profile.

it also depends on the brand and quality of the time... Alcoa Forged are pretty strong rims... i busted a sidewall out of one of the runflats and didnt hurt the rim...


on the diameter issue... you want to be as close as possible... bigger front to back is worse then bigger side to side... when i had to get a new tire (stated above) i wasnt that worried about it because left to right equalizes because of the open diffs (so 1/8" difference is only 1/16 driveshaft speed)

you could find out how far it would be off using what builder bill said...

if one has a circumference of 90" and the other is 89" then they will be 1" off every rotation...

i have also heard 3% from the engineers but think about that... 29" tall tire 3% would be .87" and i wouldn't ever think about that 1% is .3" and that even seems like a lot...

when i am looking at tires i am trying to stay .1" difference front to back which would be .314" per revolution so in 4 rev it would be off 1.25" front to back

I run 285/315 vredestein tires on my 22s. Haven't had a problem.

I run 285/315 vredestein tires on my 22s. Haven't had a problem.

what is your rim width front and back and which model of vred's.