Jllewan

I'm looking to replace my rims & tires for my 1988 951. I would like to know what the widest tire for 17" and could I go up to 18" without rubbing or rolling fenders. I want to track the car but still use for everyday driving. Thanks!

bw993

I run 18x10 ET60 wheels all around on my 951 track car, with 275/35-18 tires in the front and 295/30-18 rears. I have no issues with rubbing, but I am running full coilovers and lots of negative camber.

No Lag

I run 18’s. 8 and 10 with stock suspension and a 265 width in the rear. No rubbing.
That said most would agree the best all round option is likely 17’s for track and daily use.

SloMo228

Others have obviously posted wider tires, but just for another data point I've run 255s on 17x9s with "normal" street suspension with no rubbing.

How much power are you making?

Edit: by "normal" I mean not slammed, no super-stiff springs and not a ton of camber. 255s fit at all four corners.