Urgent TPM/fill info help please

[Deep]

I have read the manual I promise....but am still a bit confused.

Anyway, my fill info is showing positive numbers at cold temperatures. Should I deflate the tyres?


Thanks very much

[David W.]

Id want pressure correct when cold as it will go up when tyres get warm. Rears are defenatly to high at 0.5 over IMO.

[jetbox]

Isn't that saying you need to fill by 0.5 bar?

[GT4P]

Are not the correct tyre pressures set at 20*c ambient temperature so in these cold temperatures they are going to register below normal settings? Therefore if you inflate when the ambient temperature is 6*c then when the weather warms they will be overinflated?

[nsa]

http://www.porscheownersmanuals.com/2012-911-carre...

– "Fill info" display:
Display of the deviation from the required pressure (refilling pressure) at standstill.

You can read that either way, but I think it's telling you to put air in. Air pressure decreases with temperature.

[Magic919]

Those look over inflated according to the manual. I think expect you can access the actual pressures if that's easier.

[Deep]

To those saying it's telling me to inflate the tyres, I don't think that's true. The manual implies that fill info should display the numbers in negative form ie '-0.5' if inflation is required.

Thanks very much.

[Deep]

Magic919 said:

Those look over inflated according to the manual. I think expect you can access the actual pressures if that's easier.

Hi

Do you mean the actual pressures measured by the car or manually at the petrol station? The reason I ask is that the manual says something along the lines of 'tyre pressures should not be adjusted on the basis of the displayed pressures, they are for info only'

That statement has confused me even further.

Thanks

[nsa]

Let some air out then and see if the number moves closer to zero.

[Magic919]

I only check mine with a decent gauge as I have no TPM. Compare the TPM reading with your gauge and see what you think. See me say they get the same readings.

I'm suggesting you check the absolute figure the car is reading, as some people posting are unclear on whether they are high or low at the moment.

[wilkos]

I found the display on my 911 tonne spot on. Set the pressures at a petrol station. Knock about 0.1 off the required pressures for the 15-20c we are below 20c and your monitors will read +or- 0.1 bar of the garage setting.
The tpms system adjust the required pressure for temperature, so once you have the pressures set right, they will read within 0.1 bar of required pressures all the time.
I'd take some air out of your tyres!

[Deep]

Thanks very much. I'll pop into the petrol station today and deflate the tyres.

[BertBert]

Eek, I'd be getting a decent gauge rather than rely on the garage! Or is that just old fashioned?

[gsewell]

Not old fashioned, the drive to the garage will increase the pressure by a few psi depending on the distance.

[Pope]

The fill info screen shows the pressure from correct; correct is displayed as 0.0

The +0.5 means the tyre is 0.5 bar over-inflated

You have the TPM set on comfort, partly loaded - this is the lowest pressure setting designed for a comfort oriented drive with no luggage.

If you change the TPM setting to standard or fully loaded you'll see the fill info change - it will get closer to 0.0 on the over pressured tyres.

Use the fill info screen explicitly - ignore the gauge on the forecourt. Ideally set pressures cold - there is an algorithm that compensates for pressure changes with temperature.

[jimmyslr]

As a related aside, I note that a few people mention that "it's cold so pressures will be lower and that's ok". Whilst it is cold and that does make pressures lower, isn't the idea that the car runs at a certain specified pressure and that you'll need to adjust the air in the tyre over the course of the year? That's what I do.

At this time of year you can't get much heat into the tyres so they stay cold to mildly warm and don't get to the same temps as say in the summer. Given you still want the same absolute pressure for optimal handling in winter, you need more air for that and in summer less.

[Deep]

Pope said:

The fill info screen shows the pressure from correct; correct is displayed as 0.0

The +0.5 means the tyre is 0.5 bar over-inflated

You have the TPM set on comfort, partly loaded - this is the lowest pressure setting designed for a comfort oriented drive with no luggage.

If you change the TPM setting to standard or fully loaded you'll see the fill info change - it will get closer to 0.0 on the over pressured tyres.

Use the fill info screen explicitly - ignore the gauge on the forecourt. Ideally set pressures cold - there is an algorithm that compensates for pressure changes with temperature.

Thanks very much. Yes, I've been going by the fill info, I only went to the petrol station to do it so that I could top up in case I let out too much air.

Going by your post it would seem that maybe the dealer set the tyre pressures to standard/fully loaded and I've changed to comfort hence the quoted 'overfill'.

Anyway, it now looks like this. I'll see how I like the ride in comfort setting. Thanks very much

[Pope]

No worries - the system is designed to be maintained at 0.0 - you will get under-pressure warnings at -0.3 and -0.5 bar, the system doesn't supply over-pressure warnings.

Strictly speaking those figures are still slightly off - not sure anyone would feel the difference of 3psi though