So after all the work I did to my car...I do not like the ride. Feels like a brick. Don't get me wrong....the handling is GREAT. But when the road gets rough the ride is HARSH. I just bought a new set of wheels and tires for my Mustang so now I have a brand new set of 235-50-18 Pirelli tires sitting around. I'm thinking the thicker tires will soften it up some. I guess my 2 concerns are: 1. Will the 235-50-18 fit on a 9.5 inch wide rim? 2. Do you think there will be rubbing issues? BTW I removed my inner fenders.
You'll have a mild bit of stretch, but they definitely will fit safely on a 9.5" wide wheel. There's people in the import community stretching 225's and as narrow as 205's on a 10" wide wheel. You "SHOULDN'T" have rubbing issues. I found on one of my previous vehicles, that it rode better and felt more compliant with 18" wheels over the 17" I had on it previously...which seemed weird, given they both used the same tire type from the same manufacturer. Most likely due to the spring rate and rebound of my coilovers.
Here's a picture of a 235 width tire on a 9.5" wide wheel. https://tyrestretch.com/9.5-235-35-R19/9.5-235-35-R19-Falken-452/
I guess my concern is more of the tire height. I wonder if the tire will rub the fender. I suppose there's only one way to really find out.
A P235/50R-18 is 27.25" tall, so no issue with the height. As long as your wheel back space is correct, 235 section width tires should be no problem at all.