Time for change
Whilst the UK legal minimum tread depth is 1.6mm across the central three-quarters of a tyre and around its full circumference, we recommend to our customers that tyres are replaced once the tread depth reaches 3mm. This goes for all cars, but most especially high performance ones. Stopping distances in the wet increase dramatically when tyres wear below 3mm: the difference between 3mm tread depth and 1.6mm being in the region of 30%, equating to an extra 12 metres stopping distance required at a modest 50mph.
Consider that, at 60mph, a sports car tyre needs to disperse between 7 and 10 litres of water per second to maintain contact with a moderately wet road. The higher the speed and/or the more standing water, of course, the greater the volume of water that a tyre must channel away to avoid loss of traction (Formula 1 full wet tyres, incidentally, are capable of dispersing an astonishing 60 litres of water per second at 186mph when new).