What is the minimum tread depth for a car tyre?

In the UK, the legal minimum tread depth requirement for car tyres is 1.6 millimeters. This measurement must be consistent across the central three-quarters of the tyre's width and around its entire circumference. Tread depth is crucial because it significantly impacts a vehicle's handling, braking distance, and overall safety, especially in wet conditions where proper water displacement is necessary to avoid aquaplaning.

To ensure compliance and safety, drivers are encouraged to regularly inspect their tyre tread depth using a tread depth gauge or the "20p test." For the latter, inserting a 20p coin into the tread grooves can help determine if the tread depth is sufficient. If the outer band of the coin is visible, it's a sign that the tread depth is below the legal minimum, and the tyre should be replaced.

Moreover, while 1.6 millimeters is the legal threshold, many experts recommend considering a replacement when tread depth reaches around 3 millimeters. This is particularly important for maintaining optimal vehicle performance, grip, and safety during wet weather conditions. Adequate tread depth enhances traction and reduces the risk of skidding, making it a critical element of vehicle maintenance.

Regular checks and maintenance of tyres can not only ensure legal compliance but also improve fuel efficiency and enhance the lifespan of your tyres. Therefore, taking the time to monitor tyre conditions is a vital part of responsible vehicle ownership.

See also:

MOT Inspection Manual - 5.2. Wheels and tyres