i have 235/35/19 and 315/25/19 nitto inzo tires on mine and have no problems. They are within 1% of each other.

 

Stock wheels are easy, it gets complicated when you start changing wheel widths, which most of us do. If you go by tirerack, there is a chance that what starts off as equal or near equal overall diameters can be skewed by the tire's fit on the wheel. Meaning if you are on the narrower side of the tire in the rear and wider in the front. That slightly stretched tire in the back may change the oveall diameter slightly while that other tire being "big" on the wheel could now be substantially different from the back.


I've actually thought about this alot. Anyone else?

 

Well, i would say not to stretch... but apparantly its some popular euro trend.

 

On tirerack they list the 'recommended rim width range' as well as the 'measured rim width'.. I use the specs they list for diameter, revs, etc for calculations- but as a general practice I think the rim choice should be at or +/- 1/2 inch of the measured rim width. My suspicion is that if you are within a half inch of the measured rim width for your wheel, you will not have an appreciable difference.

My 2 cents

A

 

I just did a rough calculation for a typical 18" wheel and Porsche tire. The
sidewall will be about 3.75" tall, and assuming that's the maximum, based
on having the rim width exactly right to make the sidewall vertical, if you then
use a wider or narrower wheel by .5", effectively tilting the sidewall over,
the resulting change in rolling diameter might be around .008" or .2 millimeters,
essentially a non-issue. Compare .008" to tire wear from 10/32nds to 4/32nds
which makes .375" difference in rolling diameter.

 

I got 0.033 inches... but I will agree that +/- 1/2 ince is geometrically (probably) immaterial.