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To add to my theory, three of you showing this type of wear have RAS. I circled the shoulder of the tire that only sees wear in harder cornering which you can tell by the light brownish color. It shows the tires is only making contact to the ground sometimes. But within that light wear area is a very sharp line which makes me think something is rubbing. So maybe with the RAS, it turns the wheel enough to get it to rub against something. Anyone that does not have RAS show this very tight wear line?
I also doubt that camber is the problem. After lots of years with street, track, and race car set up and driving, aggressive camber (and aggressive driving) does often lead to uneven wear. But that wear is on the outer or inner edge of the tread surface, and maybe just onto the corner. I have never seen camber create wear on the corner without also wearing the adjacent tread.
Three months ago I replaced rear tires at 9,600 miles. The right rear looked like pictures above. The left rear worn on the inside but not as bad. I had a 4-wheel alignment done. The neg. camber before alignment was -2.21 on the right vs -1.56 for the left. The proper spec calls for approx -1.4 on both sides. The toe on both was ~ on spec before alignment. So, NOT a factor.
With too much camber like you had (especially on the RR wheel), what would otherwise be normal toe becomes excessive toe. And even then, was the toe "on" spec, or "in" spec? Your alignment shop just might have called the toe setting that they found to be "close enough".
Nothing is rubbing on the inners of my rears ('19 GTS with RAS) albeit just over 6k miles - I cannot see where it could rub anything with the stock suspension (PASM) so matter how hard one takes a turn.
Thanks for all the help and input. I'm going to work with my service advisor to see if they can send the photos to someone higher up in Porsche for a closer look, since I don't think this is normal wear for a 9000 mile car on a factory set-up that hasn't been tracked. I'll have them check the alignment as well.
To add to my theory, three of you showing this type of wear have RAS. I circled the shoulder of the tire that only sees wear in harder cornering which you can tell by the light brownish color. It shows the tires is only making contact to the ground sometimes. But within that light wear area is a very sharp line which makes me think something is rubbing. So maybe with the RAS, it turns the wheel enough to get it to rub against something. Anyone that does not have RAS show this very tight wear line?
On my car (at least) that is not rubbing. It's the way the PZero tire is manufactured. Clearances at the extremes of travel show at least 2" to any contact surface.
With too much camber like you had (especially on the RR wheel), what would otherwise be normal toe becomes excessive toe. And even then, was the toe "on" spec, or "in" spec? Your alignment shop just might have called the toe setting that they found to be "close enough".
Alignment was done at local Porsche dealer. Before the alignment, the toe on the right rear wheel (the one with excessive wear on the inside of tread) was "spot on" per the specs provided by Porsche for my model. After alignment camber and toe were both within spec (acceptable) "range". Hopefully I'll get better wear on the rear tires going forward.
That type of wear is not normal no matter what Porsche says. If it was they would need a special tire that could compensate for it. Having 1/25th of the tire tread completely gone is crazy
Wear on the inside of tread IS NORMAL if your 911 is set up to factory specs. On my previous 981 Cayman GTS I replaced my rear tires for the same reason at ~11k miles Come on, these are SPORTS CAR after all! If you baby the car and/or do an alignment more suited for lower performance you can get away with longer tread life. Just be glad you don't own an early Honda NSX. If you drove carefully, you might eak-out 5k miles. Just sayin'...
I agree about extreme differential wear on the inner or outer part of the TREAD and on the corner of the tread onto the sidewall, but to me this looks like wear mostly (or only) on the corner. And I doubt that comes from too much camber. It would take -45 degrees of camber to get a tire to ride only on the inner corner.
On my car (at least) that is not rubbing. It's the way the PZero tire is manufactured. Clearances at the extremes of travel show at least 2" to any contact surface.
Pzero absolute junk sidewalls. I’m not surprised by those pics.
If it is normal (not just usual) I wonder why it is happening? The camber and toe specs are not that aggressive compared to some sports cars but the tire wear seems unusually rapid on a very small area of the tire. I've had several better handling cars with more aggressive settings that don't wear tires in such a small area as pictured. And it seems to happen on different makes of tires as well.
08-01-2020, 09:39 PM
