Avon Motorsport Scrubbing in procedure
Avon Tyres Motorsport recommends a standard scrubbing in procedure be used whenever possible (When Time and Conditions allow). This consists of subjecting the tyres through one gentle heat cycle, gradually loading them up whilst avoiding drifting the car. This should take about three to four gentle laps at around 60% pace of a circuit. The last lap should only be about 80% race speed. If it is possible, scrub in at least one new set of tyres during free practice, and put these aside for the race. In this way you will know that they have been balanced correctly, and have no slow punctures etc. Getting this done early is important as the qualifying session may become wet or be red flagged, which could force the use of new tyres in a race.
It should be noted that there is always going to be a slight performance peak from new tyres, but it will only be possible to take advantage of this if the car is balanced on its tyres. A correctly scrubbed in set of tyres will always give more consistent performance over its lifetime than a set that has been used hard from new, even if it hasn't grained.