[Em135eye]

Inlaws X5 has been running too low (PSI) on 19" non run flats. So the outside edge of both tyres have worn prematurely. They are massive tyres so that £500++ down the drain.

Lesson? Check your tyres yourself regularly. £6 gets you a Michelin tyre pressure gauge that's nice and accurate.

[SoYank]

Originally Posted by E92Fan

No, there's no functional difference for the European cars. The US cars might have an actual pressure reading, but I don't remember that on Floyd's car (which is US spec). The ABS sensor does only tell you when the tyre is low as it doesn't measure pressure directly. The TPMS equipped UK cars definitely do not show the actual pressure either...

My car does not specifically point out which tyre is low on pressure. It merely announces that I have a low or flat tyre. Grant you, it's only squawked once and that was when I changed to my summer tyres in March and they were all at the right pressures. Also, I seem to recall from my 2006 E90 with the ABS version that the right rear is compared with the left front and LR with RF. Seems strange since the front tyres usually have a lower pressure than the rear ones and the system functions based on the rotation of a tyre with a certain amount of pressure. One would expect the front with its lower pressure and thus smaller circumference to rotate faster than the rear.

Originally Posted by xenon

I must be mistaken then. I also drove a Buick in the US that definitely gave individual tyre pressures on the display so it is possible. The rest of the car was a POS though so I wouldn't recommend it purely on that basis...

Different manufacturers provide different displays. The more sophisticated ones have the individual tyre pressures. One would think that BMW would fall into the more highly sophisticated category but it doesn't appear so. I was going to invest in a tyre pressure monitor system for my truck that would show which tyre was flat.

I need to find a job in the states soon. I'm back to misspelling my car parts again.

[SoYank]

Originally Posted by 335diesel

Lesson? Check your tyres yourself regularly. £6 gets you a Michelin tyre pressure gauge that's nice and accurate.

I have a nice Michelin digital tyre pressure gauge that reads six to nine PSI too high compared to several other of my nice and accurate gauges. Anyone want it? It's useless to me.

[Em135eye]

I've checked mine against a garage pressure gauge - exactly the same readings.

[Dr Dave]

Here's a set of US spec TPMS sensors, contained within the wheel/tyre itself.

[Yahoo]

Cool! How do they communicate with the car, are they magnetic?

[Dr Dave]

Originally Posted by Yahoo

Cool! How do they communicate with the car, are they magnetic?

RF transmitters (as above) and a reciever in the car