pressure

[Agile]

How do most cars monitor tyre pressure?

Do they have a transducer and wireless transmitter on each wheel?

I hired a small Citroen and that had very sensitive tyre pressure sensors.

Nice little car with a very good audio system. But only ( very bad ) tyre noise.

I thought that it might be due to the particular tyre make but the lady at the car hire place said it was not due to the particular brand.

 

[Mottie]

Some use a transducer in each wheel, others use the abs sensor.

 

[Harry Bloomfield]

Some use a transducer in each wheel, others use the abs sensor.

I would be interested to know how that works, what I read was that the rolling diameter does not change significantly with a slight loss in pressure.

 

[Agile]

On the small Citroen it would consistently register low pressure when the pressure fell below about 26 psi.

Normal pressure being about 32 psi.

 

[Keithmac]

Ours uses wheel speed (same as BMW etc) it is very accurate to be fair.

I believe November 2014 it was manditory for all cars sold in UK to have "proper" TPMS systems fitted (pressure sensors in wheels).