awilli6

I currently have 235/35/18 on the rear of my 87S4, would 285/35/18 fit?

rexpontius

depends on the wheels you are planning to use.

For sure you cannot mount 285's on the same wheels you currently have the 235's.

for 285 I think you will need at least a 10 inch wide wheel.

The height will just fit I think, but 285/30/18 would be better.

FredR

A 235 on the rear-ow did that happen? Must be like driving on a bar of soap.

There is a limited size width range that a given width can be fitted on and the range is more limited the lower the profile. The Tirewarehouse website gives you such data for specific tires/makes- I always refer the Michelin pages.

For 285 x18 tire you will need rims in the width range of 9.5 inch to 11 inch I suspect. 10 inch is optimal and you should go for a 285x30 section as this is nearly identical to the stock rolling radius.

If a 235 fits your current rims then a 285 will not I would think.

Fred

jbrob007

I currently run 275/35/18 and the wheels are 10 inch... barely fit under the lip... might take off some paint with 285... In addition, 285/30 wont leave much cushion left for pot holes, etc...

Jroman

I run 285/30 18 on the back... have plenty of room inside and out... and run w/ 5mm spacer.
CLW's 65 ET and Pirelli tires

Btw There are other posts on this subject and I think there's even a calculator

Stromius

Run a 265/35 on 18x10 with 65 ET. No spacer no issues

awilli6

I have 265/35/18 on the back. Losing eyesight in old age