What is the legal minimum for tyre tread?
In the United Kingdom and Europe the legal minimum depth for tyre tread is 1.6mm. This must be continuous, around at least 75 % of the tyre. It should also be remembered that the tyre tread regulations apply to any spare wheel carried on the vehicle.
The absolute minimum depth acceptable is 1.6mm. With further wear and tear, especially if the vehicle covers big mileage, it will not be too long before the depth of tread contravenes the law. In fact it is recommended that motorists replace tyres once the depth reaches 3mm.
Failure to meet these requirements can lead to prosecution and a hefty fine. Also, if the vehicle is involved in an accident and has defective tyres the owner's insurance company may decline to provide cover. That is why it is important for owners to regularly measure their car's tyre tread to ensure they comply with the law.
Equipment for measuring tyre tread
Measuring the tread on tyres is quite simple to do. While some people use the edge of a 20p coin as a rough guide, there are gauges available that will give a more precise measurement. Motorists are advised to purchase one of these devices, some of which can also be used to measure tyre pressure.
Measuring tyre tread
When measuring the tread depth the vehicle should be parked on a flat and even surface, in a safe place away from moving traffic. Using the tyre tread gauge, the main tread grooves should be checked in several places around the tyre. It is important to read the instructions that come with the gauge to ensure it is used correctly.
Tyres also have what are known as tread wear indicators, which are moulded into the base of the main grooves. An indication that the tyres have reached the minimum depth becomes apparent when the tread level reaches the same level as these indicators. However, if when checking the tread, it is found they have worn down to 3mm or less it is best to take the car to a local tyre centre to have replacements fitted.