Tyre pressure monitoring system.

[Manks]

I am wondering whether to add this to a new car order. I have been using it on a loan car today and it seems quite useful. However, I note that after-market systems are available at about 1/3 the price and they monitor both temperature and pressure whereas the Porsche one just monitors pressure it appears.

Any thoughts from anyone that uses TPM please?

[DSM2]

Manks said:

I am wondering whether to add this to a new car order. I have been using it on a loan car today and it seems quite useful. However, I note that after-market systems are available at about 1/3 the price and they monitor both temperature and pressure whereas the Porsche one just monitors pressure it appears.

Any thoughts from anyone that uses TPM please?

I specced it on my C2S having been in the tyre business for 25 years and being aware of how good sealant kits aren't. My display is set to the TPM most of the time and it gives me a good insight to what the tyres are doing.

I would also hope to get very early warning of a drop in pressure (which the system does not warn soon enough about in my experience) and if there is a puncture have a chance of keeping the tyre properly inflated until I get home, where I can repair it.

Having the temperature is nice but as its directly related to pressure, not essential.

Finally, contradictory to what some have said, the readings of the system are fairly accurate. I regularly check with a calibrated ALG that I have for racing and there's little in it..

[Manks]

DSM2 said:

Manks said:

I am wondering whether to add this to a new car order. I have been using it on a loan car today and it seems quite useful. However, I note that after-market systems are available at about 1/3 the price and they monitor both temperature and pressure whereas the Porsche one just monitors pressure it appears.

Any thoughts from anyone that uses TPM please?

I specced it on my C2S having been in the tyre business for 25 years and being aware of how good sealant kits aren't. My display is set to the TPM most of the time and it gives me a good insight to what the tyres are doing.

I would also hope to get very early warning of a drop in pressure (which the system does not warn soon enough about in my experience) and if there is a puncture have a chance of keeping the tyre properly inflated until I get home, where I can repair it.

Having the temperature is nice but as its directly related to pressure, not essential.

Finally, contradictory to what some have said, the readings of the system are fairly accurate. I regularly check with a calibrated ALG that I have for racing and there's little in it..

Worth £450 then?

[Wozy68]

Manks said:

I am wondering whether to add this to a new car order. I have been using it on a loan car today and it seems quite useful. However, I note that after-market systems are available at about 1/3 the price and they monitor both temperature and pressure whereas the Porsche one just monitors pressure it appears.

Any thoughts from anyone that uses TPM please?

I thought this had to be built into every new car now sold as standard?

[BnB]

Hi Manks. I've speced it on my new car.

I was using Tiremoni (a German product available from Amazon) on my old car and I'm amazed how regularly I would refer to it. Tiremoni is a bit clunky in that you have large sensors replacing the valve caps on each tyre but the information really keys you into the importance of accurate and balanced tyre pressures, something I seem to recall you were reminded of in your early days of 991 ownership.

We've switched it to my wife's car now and I'm going for the neater integration of the data into PCM with TPMS. Having had it I don't think I'd want to be without. But I'm a tart for real-time data feeds of all types.

[DSM2]

Manks said:

DSM2 said:

Manks said:

I am wondering whether to add this to a new car order. I have been using it on a loan car today and it seems quite useful. However, I note that after-market systems are available at about 1/3 the price and they monitor both temperature and pressure whereas the Porsche one just monitors pressure it appears.

Any thoughts from anyone that uses TPM please?

I specced it on my C2S having been in the tyre business for 25 years and being aware of how good sealant kits aren't. My display is set to the TPM most of the time and it gives me a good insight to what the tyres are doing.

I would also hope to get very early warning of a drop in pressure (which the system does not warn soon enough about in my experience) and if there is a puncture have a chance of keeping the tyre properly inflated until I get home, where I can repair it.

Having the temperature is nice but as its directly related to pressure, not essential.

Finally, contradictory to what some have said, the readings of the system are fairly accurate. I regularly check with a calibrated ALG that I have for racing and there's little in it..

Worth £450 then?

For me certainly.

[DSM2]

Wozy68 said:

Manks said:

I am wondering whether to add this to a new car order. I have been using it on a loan car today and it seems quite useful. However, I note that after-market systems are available at about 1/3 the price and they monitor both temperature and pressure whereas the Porsche one just monitors pressure it appears.

Any thoughts from anyone that uses TPM please?

I thought this had to be built into every new car now sold as standard?

In the USA, not in Europe.

[MadMark911]

DSM2 said:

Wozy68 said:

Manks said:

I am wondering whether to add this to a new car order. I have been using it on a loan car today and it seems quite useful. However, I note that after-market systems are available at about 1/3 the price and they monitor both temperature and pressure whereas the Porsche one just monitors pressure it appears.

Any thoughts from anyone that uses TPM please?

I thought this had to be built into every new car now sold as standard?

In the USA, not in Europe.

They're too lazy to check pressures by hand .....

[BnB]

MadMark911 said:

They're too lazy to check pressures by hand .....

While doing 70 on the motorway?

[DSM2]

MadMark911 said:

DSM2 said:

Wozy68 said:

Manks said:

I am wondering whether to add this to a new car order. I have been using it on a loan car today and it seems quite useful. However, I note that after-market systems are available at about 1/3 the price and they monitor both temperature and pressure whereas the Porsche one just monitors pressure it appears.

Any thoughts from anyone that uses TPM please?

I thought this had to be built into every new car now sold as standard?

In the USA, not in Europe.

They're too lazy to check pressures by hand .....

Dont know if you meant it that way but its quite true. A general neglect of tyres by users and questionable service led to a number of high value claims following tyre related accidents. The result was the TPMS legislation.

[David W.]

It's very difficult to see if a very low profile tyre is a little soft, and who looks regularly anyway?
The Porsche system flags up a reduction of .3 bar which warns you to both check for any obvious damage and top up asap to enable your journey to be completed. Whats not to like.
dw

[C2'S'man]

Got it on my RS and find it very useful, particularly on track days where the pressures can blow up in a very short time. The system is quite accurate and the in car display figures with a manual check every time.

Not too sure about it being so useful for normal road use where the demands on tyres are far less....

g

[Manks]

How does TPMS work by the way? How is the tyre pressure measured? Valve cap?

[DSM2]

Manks said:

How does TPMS work by the way? How is the tyre pressure measured? Valve cap?

On the 997 there is a pressure sensor fitted to the base of the valve, nestling just in the wheel well. Need to be careful removing or fitting tyres, they can be damaged.

The sensor has a battery which lasts 6 or 7 years and then you change the whole valve.

The reading from the sensor is picked up by a receiver close to the wheel, (I stand to be corrected on this point) and fed to the OBC..

If you swap the wheels on an axle, the system needs to relearn which sensors are at which corner and can be thrown, needing an OPC reset. I know this from experience.

Final point, don't fit metal valve caps. The valve stems aren't brass and corrosion can cause the caps to seize on, needing a new valve

[Ozzie Osmond]

The catch in UK is the latest MOT changes say "if a new car is fitted with TPM then it's an MOT fail if the system isn't working".

If you get a dodgy sender (the battery powered bit fitted inside each wheel - the batteries eventually die) then,

• Wheel off
• Tyre off
• New sender
• Tyre on
• Balance wheel
• Wheel on
• Reprogram main car unit to recognise the new sender.

In a word, it's expensive if/when it goes wrong.

Because of that, every time you buy new tyres you're left wondering, "should I get all the senders changed as a precautionary measure while the tyres are off?"

Also, although it can tell you you've got a flat it can't fix the puncture! I'd have thought the driver of a mid-engined car would feel a tyre going down reasonably early in any event.

It may be less hassle and expense just to get trailered home if/when you get a flat rather than spending £450 for installation and then the maintenance costs. Mind you, it ought to be included in the base price of the car these days.

[DoubleSix]

DSM2 said:

On the 997 there is a pressure sensor fitted to the base of the valve, nestling just in the wheel well. Need to be careful removing or fitting tyres, they can be damaged.

The sensor has a battery which lasts 6 or 7 years and then you change the whole valve.

The reading from the sensor is picked up by a receiver close to the wheel, (I stand to be corrected on this point) and fed to the OBC..

If you swap the wheels on an axle, the system needs to relearn which sensors are at which corner and can be thrown, needing an OPC reset. I know this from experience.

Final point, don't fit metal valve caps. The valve stems aren't brass and corrosion can cause the caps to seize on, needing a new valve

Interesting. My understanding was that TPMS work by detecting minute changes in wheel rotation, a quick read on wiki show there are indeed two types...

[Manks]

Ozzie Osmond said:

The catch in UK is the latest MOT changes say "if a new car is fitted with TPM then it's an MOT fail if the system isn't working".

If you get a dodgy sender (the battery powered bit fitted inside each wheel - the batteries eventually die) then,

• Wheel off
• Tyre off
• New sender
• Tyre on
• Balance wheel
• Wheel on
• Reprogram main car unit to recognise the new sender.

In a word, it's expensive if/when it goes wrong.

Because of that, every time you buy new tyres you're left wondering, "should I get all the senders changed as a precautionary measure while the tyres are off?"

Also, although it can tell you you've got a flat it can't fix the puncture! I'd have thought the driver of a mid-engined car would feel a tyre going down reasonably early in any event.

It may be less hassle and expense just to get trailered home if/when you get a flat rather than spending £450 for installation and then the maintenance costs. Mind you, it ought to be included in the base price of the car these days.

I don't think the expense is a big issue but I am going off the idea a bit. I had originally wondered about it to determine tyre pressures / temperature for fast driving but I pretty much know when tyres are hot anyway.

[oz996]

I was using the Orange TPMS but after less than a year 3 of 4 sensors failed. So I have binned it as of my last tyre change. Based on that experience I wouldn't recommend that particular system, although it was 'nice' having that pressure information available.

[Martian O]

DSM2 said:

Wozy68 said:

Manks said:

I am wondering whether to add this to a new car order. I have been using it on a loan car today and it seems quite useful. However, I note that after-market systems are available at about 1/3 the price and they monitor both temperature and pressure whereas the Porsche one just monitors pressure it appears.

Any thoughts from anyone that uses TPM please?

I thought this had to be built into every new car now sold as standard?

In the USA, not in Europe.

And on new Euro cars from November 2012 IIRC.

[Manks]

Mine is due September. Wonder whether it will be on mine.....