[mikes2]

the only tyre in 245/40ZR17 which can be fitted to the 7" Cups on the RS2 are Dunlop SP8000. These were specially comissioned by Dunlop when the cars were new. No other 245 section tyre is approved for fitting to a 7" rim

SP8000s have been out of production for a long time and are not available.

You'll need to fit 225/45ZR17