Tire pressure after buying

[tchavei]

I doubt they test this so thoroughly.

this morning started very cold here (17 C ?) and my tires were showing 2.6 bar all around, the differential still shows +0.4 bar in fronts and 0.2 bar in the back. I'm not going to run those tires at 2.2 bar, I'm sorry. The air suspension is fantastic. 2.7 doesn't feel stiff at all. If that's a mistake, we'll see in the future. Tyers are Goodyear Asymmetric 5 btw.

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[Scandinavian]

I'm not going to run those tires at 2.2 bar, I'm sorry. The air suspension is fantastic. 2.7 doesn't feel stiff at all. If that's a mistake, we'll see in the future. Tyers are Goodyear Asymmetric 5 btw.

On 21” tyres, 2.2 bar seems very low? Have you asked the service guy what he thinks about it? Since you upgraded your wheels, I think, the plaque in your car would not show the correct values, but the PCM, set to 21” should be correct.

 

[satchurator]

Check you PCM for recommended pressures for full load or partial load. The door sticker is old tech and probably outdated by the time it's put on the car. Use partial load if you want lower pressures (unless you have your Taycan loaded with 400kg of crap).

This is the way. People fixate on the door jam sticker. In the USA, that label is a federal requirement (NHTSA) upon auto manufacturers, and applies to the original equipment i.e. the tires that the car was shipped out on. It's an inherent compromise.

Use the PCM or manual to determine the correct target pressures for your given wheel radius, tire type and load.

 

[simcity]

This is the way. People fixate on the door jam sticker. In the USA, that label is a federal requirement (NHTSA) upon auto manufacturers, and applies to the original equipment i.e. the tires that the car was shipped out on. It's an inherent compromise.

Use the PCM or manual to determine the correct target pressures for your given wheel radius, tire type and load.

Yep and to be clear…..

1. There are at least 2 variants of the tyre plate:

a) your federally mandated yellow and white sticker in the states / Canada - just one ‘universal’ pressure noted.

b) the black metallic plate for cars in EU and UK - partial and full load pressures noted

2. the wording / directions in the electronic manual vary from geography to geography. In EU /UK countries the manual does not list any tyre pressures. It points you to read the black tyre plate.

 

[tchavei]

On 21” tyres, 2.2 bar seems very low? Have you asked the service guy what he thinks about it? Since you upgraded your wheels, I think, the plaque in your car would not show the correct values, but the PCM, set to 21” should be correct.

Indeed it seems too low. And yeah, they're 21'' and set in pcm as 21'' summer.

I'm not sweating it. Car drives like on rails. If the tyres wear out prematurely, I'll lower it on the next set.

I usually have the opposite problem in my other cars. I don't check tyre pressures as I should (maybe every 2 months) so sometimes they get low and wear faster on the outside.

 

[Scandinavian]

Indeed it seems too low. And yeah, they're 21'' and set in pcm as 21'' summer.

I'm not sweating it. Car drives like on rails. If the tyres wear out prematurely, I'll lower it on the next set.

I usually have the opposite problem in my other cars. I don't check tyre pressures as I should (maybe every 2 months) so sometimes they get low and wear faster on the outside.

Maybe worth having a conversation with your service guy anyhow. Perhaps the PCM was not programmed correctly for 21’s?

There is a sentence in the manual of the app that triggered my response. It seems the Service guys can add dimensions and settings in the PCM, should you put on tyres that are not displayed from start?? Perhaps there is a mistake in the entry. See screenshot of app manual.

I understand that your car did have the tyre option and you selected the 21 inch but…. ? ?‍?‍

 

[tchavei]

Maybe worth having a conversation with your service guy anyhow. Perhaps the PCM was not programmed correctly for 21’s?

There is a sentence in the manual of the app that triggered my response. It seems the Service guys can add dimensions and settings in the PCM, should you put on tyres that are not displayed from start?? Perhaps there is a mistake in the entry. See screenshot of app manual.

I understand that your car did have the tyre option and you selected the 21 inch but…. ? ?‍?‍

I'll give them a call.

 

[GREATST]

Full load/partial load makes a difference in expected values, as do different tires (winter/summer/all-season) and tire sizes. You can see the expected cold pressure for the tires you have on in the PCM. For my 20" all-seasons (factory tires actually) it expects 35 psi all around at half load. That said, I adjusted the cold pressure to the desired 35 on mine on cold tires at 40F, but the car would still show 1psi over, even when the tires were showing 34 psi (so 1 under). Fine, so I let 1 psi out of each tire, which finally started showing 0psi differential. Then a few days later the differential started showing +1psi again (for all tires). Somehow I doubt the Taycan pumped up its own tires, so it had to be the warmer weather we got very recently, but according to the manual the car should have compensated for the temperature already, which to me means that the temperature compensation is not very precise on this system.

Agreed. Disconcerting.

 

[GREATST]

Full load/partial load makes a difference in expected values, as do different tires (winter/summer/all-season) and tire sizes. You can see the expected cold pressure for the tires you have on in the PCM. For my 20" all-seasons (factory tires actually) it expects 35 psi all around at half load. That said, I adjusted the cold pressure to the desired 35 on mine on cold tires at 40F, but the car would still show 1psi over, even when the tires were showing 34 psi (so 1 under). Fine, so I let 1 psi out of each tire, which finally started showing 0psi differential. Then a few days later the differential started showing +1psi again (for all tires). Somehow I doubt the Taycan pumped up its own tires, so it had to be the warmer weather we got very recently, but according to the manual the car should have compensated for the temperature already, which to me means that the temperature compensation is not very precise on this system.

Clusterstumble.

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