Race tyre sizes for Road Cars

[gbk]

Many apologies if this has been posted before but I have tried searching with no luck.

I currently run a Noble M400 with standard tyes (Pirelli P Zero Corsa) I am looking to buy some used Race Wets but the sizes are listed differently.

Is there a web site with comparison tables or calculator.

Cheers

Barry

[grahambell]

The competition department of Avon Tyres might be able to help.