Bridgestone warns that vehicles equipped with run-flat tyres should always be fitted with a Tyre Pressure Monitoring System (Tyre PMS). Bridgestone issued this warning after recently launching its DriveGuard run-flat tyre for vehicles which were not originally available with run-flat tyres.
“The main purpose of a run-flat tyre is that the driver can continue driving for some distance after a puncture until a safe location is found to repair the tyre,” said Bridgestone’s General Manager for Field Engineering and Technical Services, Hiroshi Nakanishi.
“But if drivers fit run-flat tyres to a vehicle which doesn’t have a Tyre Pressure Monitoring System, they will not be alerted when a puncture occurs, since these tyres do not show much change in handling characteristics after pressure loss.”
Nakanishi said the danger was that the driver would continue to drive on the punctured tyre at normal speeds for long distances instead of being alerted to reduce speed and change the tyre as soon as possible. This could damage the tyre, possibly causing it to disintegrate and even leading to loss of control.
“A proper Tyre PMS that is correctly installed is a vital piece of safety equipment on cars which are fitted with run-flat tyres,” he said.
Vehicles which are equipped with run-flat tyres at the factory, such as BMW, Mercedes-Benz, Audi, Lexus and similar luxury brands, are fitted with a TPMS as standard, but when run-flats are fitted to other vehicles such as Toyota, Hilux, Volkswagen, Nissan, Ford and others, a TPMS must be installed at the same time.
The TPMS units installed in vehicles to which Bridgestone DriveGuard tyres are fitted include light-weight sensors for each wheel and a control unit which displays the system status.
The TPMS must be correctly set up so that it is able to monitor each tyre for pressure loss.
“The setup procedures for factory-fitted systems are given in the vehicle’s owner’s manual and the procedure for the TPMS fitted with DriveGuard is explained to the vehicle owner when the tyres are fitted,” said Nakanishi. The TPMS must be re-set whenever the tyre is replaced or rotated.
“The most important thing to remember is not to drive a car which has run-flat tyres unless it has a functional TPMS,” Nakanishi explained. “At best you could damage a tyre beyond repair and at worst an overstressed punctured tyre could disintegrate and cause you to lose control,” he concluded.