[Graham]

A entrant asked me to define whats acceptable regarding tyre swelling, basically if on of the tyres is measuring 10mm and the other is a little over I am not going to penalise anyone. If both tyres are more than 10mm using whats obviously oversize tyres I will penalise them, ask them to change them or disqualify their car. You often get tyres swelling differently. So I will not hold everyone to exactly 10.00mm. I usually measure the tyres a few times over several days, if I think they are likely to be penalised, in order to ensure I am being fair and not just because I had a grumpy day, or my calipers were acting up etc. And often tyres  which have been treated will loose their swelling over a number of days, so they might well be compliant  by the time we get started.