Thank you both, I remembered this morning that there is a race series based on the Toyos with McMillan as one of the sponsors, so I spoke to them. They said for track use Cold - 21 front, 20 rear Hot - 25 front, 24 rear. They also said that if your car has been setup for Avons you will need the car flat floored. They charge £140+vat which seems very reasonable so I'm getting it done next week. In the meantime I'll play around and see what feels right with the current setup. One other point worth mentioning if you make the switch, is that it's worth checking tyre clearance on the front with the mudguard stays as one of my tyres was rubbing slightly, so I've had to bend back the stay. It was never a problem with the Avons. Regards Gerard