Sorry to all you American readers – we’re using the international spelling of tyre for this one!
A Tyre-Pressure Monitoring System (TPMS) constantly monitors tyre pressures and will generally alert the driver if the pressure in any tyre drops below a pre-determined level.
Tyre pressure monitoring systems enhance safety, provide better fuel economy (as properly inflated tyres roll with less resistance than under-inflated tyres – less resistance means less drag which means less fuel usage), and increase the life of tyres as under-inflated tyres wear faster.