scxtasy

I have two sets of Kinesis Mach V wheels that I got with my 964 when I bought it. Both sets have 17x8.5 inch front rims and 17x10 inch rears and are shod with 245/40R17 and 275/40R17 tires respectively (Toyo R888s on one set and Hoosiers on the other). Both sets of tires are well past their prime and need replacing. Although it looks like I can get a new set of Hoosiers or Toyo R888s or R888Rs in these sizes, there seems to be nothing else that will fit. I can go up to 255 width on the fronts (in which case there is a much broader selection of tires available), but changing the rears to 265 or 285 widths yields little change in availability. Anyone have any thoughts on tires that might work, or any other suggestions?

burglar

255/40-17 RE71R are approved for use on a 10" wheel. Would pair nice with a 235/45 on the 8.5" fronts. The 'stone runs pretty wide for its listed size, and would be real nicely supported in the sidewalls with that big wheel. Killer AX tire, but can overheat on the track easily and isn't the best street driving tire.

If you want something a little more daily drivable, the Continental EC Sport comes in a 275 & 285/40-17. They're comparable (actually slightly better than) the old Michelin Pilot Super Sport, but not quite as good as the replacement Michelin PS4S. Great summer DD tire that can also stand up to some light track work or run some AX runs.

edfishjr

You can also get the BFG Rival S 1.5 in 245/255-17
I think it's a better street tire than the RE71R... much quieter as it wears, for instance (maybe especially important in a 964) but tremendous dry grip.

sjfehr

Depends on driving style and surface. RE-71R has a stiffer sidewall and seems to couple better to our soft-sprung camber-challenged cars, and gives slightly better maximum grip. RivalS works better at higher slip angles, and seems to be preferred for Corvettes because of available size and ability to hold down more power on corner exit. Both are top tires, though, and the net differences seem to be within the noise and down to driver preference for most cars.

964 has soft suspension and not an obscene amount of power, so RE-71R would probably work better unless the driver likes a really lose car, in which case RivalS might be the right choice. The other potential decision factors are that RE-71R works better in colder temps than RivalS and is better in the wet. It thus also makes a better dual-use daily-driver/autocross tire. They both overheat quickly on the track (though you'll have some excellent times those first few laps...).