After my bent wheel episode yesterday, the TPM warning came on for the first time.

After fitting the spare, which is a different size, it took the system about 2 miles or so to detect that the wheel was different and then came on and told me to check tyres. It wouldn't let me reset it until I had stopped the car, turned it off and restarted it again. I opened the door in-between and kicked the tyre!

I had to repeat the exercise when I changed the wheel back as I forgot to reset once the winter tyre was back on.

The time to respond worries me. If I had a puncture, how long would it take to warn me that I had a puncture? would I have wrecked the tyre before it warned me?

It didn't go off when my wheel was bent, but I did stop within a couple of hundred metres, and the tyre had hardly deflated, but it was losing air.

Mike

I too am dubious of the TPM. It seems that it registeres a warning only after a drastic drop in pressure...which you'd surely be able to feel anyway due to a change in handling. :wonder:

Don't forget, it works off the ABS sensors detecting a difference in rolling diameter between two tyres. But it needs to be 'blind' to the difference between a brand-new tyre and a bald one on the same axle (a couple of inches FWIW). ISTR my old Renault had funny valves on the wheels, but whether they were anything to do with the pressure monitors, I don't know...

I too am dubious of the TPM. It seems that it registeres a warning only after a drastic drop in pressure...which you'd surely be able to feel anyway due to a change in handling. :wonder:

I must admit I was caught out by the TPM in a different way - as there had been no warning for a few weeks I'd presumed the tyres were all at the correct pressure. However when I checked them they were all a few pounds under inflated. Having thought about it the TPM only registers a relative drop in pressure in one tyre and not a general drop across all four tyres over time. Obvious really :S

It's interesting that it doesn't immediately respond to a change in wheel diameter but I still think it's a useful feature as, in my experience, most punctures result in a slow puncture rather than a quick deflation.

Hmmm... This does sounds like a dubious system then if it takes that long to respond! But then the difference between the two inflated tyres was marginal perhaps? It should be more with a big puncture or blow out. We have all driven unknowingly for hundreds of miles with slow punctures I'm sure... And for those it will take a few miles to register enough deflation. I'm yet to see mine light up.

I'm yet to see mine light up.

Long may that continue.

Mike

Long may that continue.

Mike

Oh I sure hope so as well!

I too am dubious of the TPM. It seems that it registeres a warning only after a drastic drop in pressure...which you'd surely be able to feel anyway due to a change in handling. :wonder:

My TPM on my new Octavia (sadly gone - but now awaiting Yeti) warned me very soon about a slow puncture. So soon that at first I thought it was a false alarm and reset it thinking that I would regret having ordered the option. Didn't take it long to "tell me" that I had a big nail in my tyre - repaired free by Skoda dealer who like me suspected it had been there on delivery.

We have TPM on our Yeti and whilst I agree that it takes a significant drop in pressure to activate, it it useful when it advises you of a problem before it becomes dangerous.

We had a nail in one of the rear tyres and it activated before there was any visible sign of the tyre being partially deflated (yes I know we're supposed to check tyre pressures daily, but we live in the real world of work and kids and lack of time, etc., etc.!). So it alerted us to a problem that we checked out and rectified before it affected the handling of the car, so on that basis I reckon it's worth having.