Hello. What tire sizes (other than 215/65-R15) can I run on a 1991 RS without doing any modification? I would like to get into the 50's but am worried about the tires rubbing.

Thanks for your help
Scott

 

235/60-15 all the way around. 245/50-15 all the way around. a little shorter though. 265/50-15 rear. if you don't mind the split size, do the 235's front and 265's rear

 

As long as you are happy with non-performance based tires. I tried in '98 to get a really good tire wider than a 225/60R15, and couldn't find anything worth mentioning. There just isn't much demand anymore for the performance 15" tire sizes anymore. We are just lucky that there are still some 16s around. If you have an option when selecting tire sizes and diameters, go with the smaller diameter, though nothing less than about 24" Your speedo will be out but that can be easily changed by using a different color of plastic gear that sticks into the side of the tranny. There is info avail. The reason for the smaller rather than taller tires is that you will get a better centre of gravity with the smaller tire. Also the resultant gear ratio will be somewhat lower, allowing better acceleration. My advice is to get 16" wheels and then take advantage of the wider wheel as well as the better rubber compounds.

 

The biggest tire you can put is 275/40/17, wheel width 9,5, with a backspacing of 5,5 , front and rear are the same.

 

Dunlop SP8000's come in 245/50ZR15. Not top-shelf, but a decent performer (although they're not very good in snow). $126 each at www.tirerack.com .

But since it's probably only a matter of time before performance 16's become as scarce as performance 15's are now, just go straight to the 17's if you're going to get new wheels.

Norm