Check Your Tires!

[Scandinavian]

If you tell your PCM what tires (size, summer/winter/all-season) you have, along with full or half loading, it will tell you what tire pressures are expected.

Yes this is what I have done all the time as well. I do have a small notice somewhere in the car as well. But nothing more specific. I always try to have about 0.1 bar higher pressure than what the PCM states. But no more than that, just to avoid any fluctuations on the negative pressure deviation.

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[Scandinavian]

Do you know what the pressure specs on these tyres are? I've asked Porsche several times but they are not very helpful. They told me to use the PCM pressure measurements and top up as appropriate

As I said in another post, I have used the PCM to adjust my pressure. I have not found any official documentation for the specific tyre. However I have seen an official Porsche document (enclosed below) that state a different value for 21 inch wheels? I only noticed this just now, so can only assume Porsche have adjusted the general recommendation to my specific tyres GoodYear?? But I may be wrong. I will ask the service guys next time I bring in the car for the brake hose recall.

The value for the front tyres are the same , but the rears are stated as 2.6 bar in the PCM??

But I did not see any uneven wear on my rears using the PCM pressure recommendations.

 

[chun]

This year i've put close to 15.000km on my summer pireli pz4s; which already had 4-5000 km as i bought them together with used 21 mission-e. So a total of 20.000 easly on them.

Beside the rear tires being close to their end of life, not much tread depth left, i do not have this weird inner excessive wear on the tires. They are for sure a bit more worn out on the inside, but nothing excessive.

To mention, front tires could easly go another 10000 km.

My tires have been anywhere between 43 and 41 PSI over the months (all 4 equal PSI)

I ride in the lowest setting 90% of the time.

I often throw the car around corners at high speed; using individual mode (all the way lowered, sport plus suspension / chasis, normal drive mode).

So my guess is that the cars showing this issue have horrible missaligment issues; and they should be taken to a shop where they check alignment in all drive modes / heights.

To add: why would the PSI between a turbo and a 4s differ so much in recommandation? I think people might be following recomandation of 35PSI, and then lower their car all the way down, and porsche probably espected 4s owners to just not throw their car around and have it lowered. Would advise owners to just use the turbo s recommandations no matter what model you have

 

[Vim Schrotnock]

I think it definitely is alignment. Not in the context of being "out of spec", but in the whole design of the car and, particularly, the differences between its different suspension modes.

Tyres simply don't wear this way if alignment is right.

The video posted by wafergold is interesting and it looks like that company does something that makes logical sense to me, in terms of adjusting settings in "Normal" so that the impact of "Sport Plus" doesn't take it as far out of spec. But all of these things will be relative and there'll only be so much that can be done with the fundamentals of the car's set up.

I think it definitely is alignment. Not in the context of being "out of spec", but in the whole design of the car and, particularly, the differences between its different suspension modes.

Tyres simply don't wear this way if alignment is right.

The video posted by wafergold is interesting and it looks like that company does something that makes logical sense to me, in terms of adjusting settings in "Normal" so that the impact of "Sport Plus" doesn't take it as far out of spec. But all of these things will be relative and there'll only be so much that can be done with the fundamentals of the car's set up.

If you read through my attached thread, you'll see that there was nothing significantly wrong with my alignment measurements that would explain the extreme wear.

https://www.taycanforum.com/forum/t...trophic-tire-failure.16788/page-6#post-311239

Of course, there must be an alignment issue at some settings, or situations that caused the inner shoulder to wear through to the cords while the tread wear across the tire width was normal. My guess is the problem is related to the 'low' setting of the suspension, or perhaps 4WS, but I don't see enough data to make this case.

 

[f1eng]

I just looked at a photo of the suspension geometry.
I am only familiar with racing car geometry requirements but the camber gain is huge with very short top link, in fact both wishbones are very short.
If I were running the car low frequently I would adjust the camber settings for that height, not normal, since the cambers are pretty aggressive already IMO.

If you use full throttle often at low ride height this sort of wear is no surprise to me now.

 

[Murph7355]

I just looked at a photo of the suspension geometry.
I am only familiar with racing car geometry requirements but the camber gain is huge with very short top link, in fact both wishbones are very short.
If I were running the car low frequently I would adjust the camber settings for that height, not normal, since the cambers are pretty aggressive already IMO.

If you use full throttle often at low ride height this sort of wear is no surprise to me now.

When I get my alignment checked, that was what I was going to do - get the camber set at the lower height.

I'm also sure there's a faint "whirring" when in the lower modes, that I'm wondering if it might be the merest bit of contact with the tyres.

 

[f1eng]

When I get my alignment checked, that was what I was going to do - get the camber set at the lower height.

I'm also sure there's a faint "whirring" when in the lower modes, that I'm wondering if it might be the merest bit of contact with the tyres.

Makes sense.
The main reason I stuck with a CT rather than changing my order to ST was the higher ride height and extra 15mm of wheel travel for the dire roads around here and it works exceptionally well at "normal" so my car will only be low at speed on the motorway when full throttle is pretty well never required.

 

[RAHRCR]

I have nearly 28K miles on my CT 4S. I run at the low or very low heights 90% of the time. I am coming due for new rubber and am planning to do the swap without an alignment because I am happy that the car tracks straight and the tires have worn very evenly. Crazy?

 

[rim23]

Am I done as well? ?

 

[bn8959]

This makes me wonder about the people timing their launches. I wonder if Normal height would actually yield more grip and faster times. With that much camber and inner edge wear, clearly there can’t be optimal grip on those low levels.

 

[Murph7355]

Front tyres now shot and just replaced

One with cords showing right on the edge, one almost there.

12k miles on one of them and, of course, the vast majority of the tyre was barely worn.

Tyre place did a quick look at alignment and think it's out, so need to get it booked in. Just mulling over whether to take it to the place linked to in a vid on here...somewhere with Taycan experience.

 

[Wakesurfer]

I have nearly 28K miles on my CT 4S. I run at the low or very low heights 90% of the time. I am coming due for new rubber and am planning to do the swap without an alignment because I am happy that the car tracks straight and the tires have worn very evenly. Crazy?

Pretty much the same for me - just replaced all 4 at 22,000 miles. I keep the car in SportPlus 100% of the time. Inside tire wear from the increased camber...................but the car looks and drives cool - and tracks really well. Why change? Tires are just a 'tool' and need to be replaced when they wear out. I am much more interested in aggressive cornering than I am in saving the tires...............but that's just me.

 

[Jonathan S.]

^ If you are always in Sports Plus, would you be able to perform an alignment so that it is optimized for that ride height? (Or does the extra camber enhance handling performance?)

 

[RAHRCR]

^ If you are always in Sports Plus, would you be able to perform an alignment so that it is optimized for that ride height? (Or does the extra camber enhance handling performance?)

Not sure but I have a CT….from what I have seen, the anlign issues are more prevalent with those that are running the sedan.

 

[Jonathan S.]

Not sure but I have a CT….from what I have seen, the anlign issues are more prevalent with those that are running the sedan.

Hmm, interesting, I hadn't thought about that, but ...

... the vast majority of all issues here are reported for the sedan, since the CT/ST is so rare in the U.S.
(Although a recent report from Norway observed the exact opposite ratio.)

The CT/ST ride height is higher than the sedan.
But the increments between the different modes are the same across both body styles.
So I think the relative effect of driving in Sport+/Low would the same for CT/ST vs sedan?

Personally, I had a little over 20k miles in my CT on a set of CC2 tires.
Treadwear looks even.
I mainly drive in my Individual mode that IIRC uses the stiffer suspension setting yet maintains the normal ride height.
But perhaps also about 20% in Sport+.

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