Run-flat tyres

Peace of mind, but limited capability after a puncture

You might want to consider run-flat tyres next time you change your car

You might want to consider run-flat tyres next time you change your car

If you worry about getting a puncture, whether because of concerns about your personal safety or simply because of the cost and inconvenience of getting the tyre repaired, you might want to consider run-flat tyres next time you change your car. Test drive them first though as the ride may be firmer and tyres more expensive and harder to get repaired.

Run-flat tyres have either a reinforced sidewall or additional internal structure to provide partial support to the tyre in a deflated condition and are being offered by more and more manufacturers on new cars.

If you do get a puncture in a run-flat tyre you might not notice, particularly on a motorway, because the ride quality will be very similar to normal. This is why run-flat tyres are always fitted together with a tyre pressure monitoring system (TPMS).

There will be restrictions on use following a puncture. The vehicle handbook will give details but in general deflated tyres should be capable of at least 50 miles (range can vary with vehicle load) at speeds up to 50 mph. Tyres should be renewed or repaired as soon as possible following a puncture.

You should get worn or damaged, run-flat tyres replaced by the same make of run-flat tyre. The TPMS will probably need to be reset after a new tyre has been fitted. Check the handbook for details.

Repairing run-flats

It is a basic principle of tyre repair that the repairer must inspect the tyre internally to check that it is safe to repair.

The repairer will consider the damage and condition of the tyre taking into account rules laid down in the appropriate standard (BS AU159f). These cover the position of the puncture in the tyre and the presence/extent of any secondary damage - damage that has occurred as a result of running in a deflated condition.

By definition, run-flat tyres are likely to have been driven 'flat' at speed for a considerable distance and this must be taken into account when considering the possibility of a repair.

The construction of run-flat tyres can make it difficult for the repairer to identify any secondary damage. This means that even though Run-flat repair kits are available to the trade, many repairers may be reluctant or simply refuse to repair a puncture in a run-flat tyre.

(25 April 2012)