Perfect pressure

Under-inflated tyres can be deadly— both for motorists and pedestrians.
So Goodyear has developed a system in which pressure sensors fitted inside the
tyre are connected by radio to indicators on the dashboard (WO 01/36220/1). The
sensors, which are bonded to the inside surface of the tyre during manufacture,
are coupled by a pair of coils to an antenna that runs round the outside. A
radio transmitter mounted on the car induces a current that powers the sensors.
So the driver gets an early warning of leaky tyres.