Motor vehicle manufacturers choose the type, make, size, profile, load carrying capacities and speed ratings to match their vehicles, adjusting the tyre pressures to give the optimum grip, ride and handling characteristics. Only change the type of tyres on your vehicle on expert advice from the vehicle manufacturer, or tyre manufacturer.
Pay special attention to the amount of tread remaining on your tyres, and measure them regularly (details of minimum legal tread depths is given below). Always replace tyres before they reach the legal limit.
The vehicle's handbook provides guidance about how to look after your tyres. It will also contain information about vehicle loading and the required adjustments to tyre pressures which should be followed for safety. Tyre pressures should always be checked and corrected (if necessary) when they are cold. It is vital that tyre pressures are maintained at the levels recommended by the manufacturer to ensure maximum tyre life, safety, the best ride and handling characteristics.
Over or under-inflating tyres is likely to seriously impair their performance and may prejudice the safe use of the vehicle. Over-inflation increases overall tyre diameter, decreases the amount of tread in contact with the road, decreases sidewall flexibility and affects road-adhesion. Under-inflation decreases overall tyre diameter, increases sidewall flexion, generates higher tyre operating temperatures and difficult vehicle handling characteristics. Running an under-inflated tyre may cause premature tyre failure. Both over and under-inflation adversely affect tyre life.
Keep tyre treads clean of stones and other foreign bodies, and check regularly for damage to the tread and side-walls. It is vitally important that any damage is checked out by a tyre expert and any necessary repairs or replacements are carried out immediately.
Check tyre valves carefully. Ensure the caps are in place and that there is no evidence of cracking or damage to the valve stem.