A car driver busily changing a flat tyre at the side of the road has become a rare scene nowadays. Mostly, this is due to run-flat tyres,  which let you keep driving after a puncture so you can make it to an auto shop for a repair.

Some auto manufacturers are making these tyres standard in new vehicles as the additional cost of four run-flats is less than the cost of a spare tyre, wheel and jack.

Run-flats vary as to how far they can be driven and at what speed, but generally speaking they can be driven for up to 80km at a reduced speed (usually about 80km per hour).

You can tell if your car has run-flats by looking inside the driver’s door, in your owner’s manual or checking the tyre’s sidewall for one of the following codes: RFT, DSST, ROF, RFT, EMT, XRP, ZP or ZPS.  In a puncture situation, run-flats are more stable than conventional tyres.  

All cars that are compatible with run-flat tyres have a tyre pressure monitoring system (TPMS), which is designed to alert the driver in the event of loss of air pressure.

Without a TPMS system, it would be almost impossible to detect a puncture, given that run-flat tyres will continue to work even when they are deflated.

Most TPMS systems display an alert on the centre console, reminding the driver that they should stop driving after 80km and seek a tyre repair or replacement.