Tread Depth

Tread depth is the vertical measurement from the top of the tyre tread to the bottom of the tread grooves, typically measured in millimetres. New car tyres start with approximately 8mm of tread. The legal minimum tread depth in the UK is 1.6mm across the central three-quarters of the tread, around the entire circumference. However, most safety organisations recommend replacing tyres at 3mm. Each illegal tyre can result in a fine of up to £2,500 and 3 penalty points.