Tyres on cars, light vans (not exceeding 3,500kg gross weight) and light trailers must have a tread depth of at least 1.6mm* across the central three-quarters of the breadth of tread+ and in a continuous band around the entire circumference of the tyre. * For goods vehicles over 3.5 tonnes the minimum tread depth requirement remains at 1mm (along with other requirements). + Breadth of tread means the width of that part of the tyre which is in contact with the road surface under normal conditions. Fig below
There are many individual causes of tyre troubles. However, the three abuses which will cause most problems, and the greatest costs, are under-inflation, overloading and speeding
Over-inflation
Over-inflation has resulted in the central tread area being forced into contact with the road causing rapid centre and worn shoulders.
Under-inflation
Under-inflation has caused this tyre to wear on the outer edges of the tread, leaving the central tread area far less worn