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Discussion Starter #1
My fronts are lasting OK, but the inner tread is considerably more worn than the center and outer. The miles are about 50-50 between normal highway and very curvy highway, with long curves that pull .5-.7G at 60+ mph, unscientifically. I used to run a lot of very tight roads, all 2nd gear, and "drive outside the envelope of my alignment" according to old sage tire dude, but these tires have only seen the spirited commute, for the most part.

Pressure has been 33psi cold (Boxster S 981 spec) but up to 36psi by the time the fun starts.

Thanks for any thoughts.
 

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Have you checked the camber? Excessive camber in the front suspension can cause wheels to lean too much to the inside thereby putting too much load on the inner side of the tire.
 

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Have you checked the camber? Excessive camber in the front suspension can cause wheels to lean too much to the inside thereby putting too much load on the inner side of the tire.
or check the front toe setting.
 

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or check the front toe setting.
Yeah, this sounds like front toe out. It's not necessarily intuitive, but a little negative camber doesn't impact wear much, but add a little toe out and the inside corners will just disappear. Have your alignment checked and have your front toe changed to neutral or a little toe in.
 

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Discussion Starter #5
Yeah, this sounds like front toe out. It's not necessarily intuitive, but a little negative camber doesn't impact wear much, but add a little toe out and the inside corners will just disappear. Have your alignment checked and have your front toe changed to neutral or a little toe in.
Totally makes sense, and thanks to all. Got it: good alignment shop.
 

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Please post what you find from the alignment shop.


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Discussion Starter #7
A little update. Good mechanic and good alignment shop next door both agreed that the wear wasn't alarmingly uneven and that I should get new tires. Ordered today, having them put on by the alignment shop and will ask them to do an alignment check. I expect to stay with stock settings.

Not dramatic, but gave me full-on motivation to order a new set of PS4S. Pretty excited about that.
 

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a bit late to the thread but I would suggest more autox or track time to get some wear on the outer shoulder :)
 

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Discussion Starter #9
a bit late to the thread but I would suggest more autox or track time to get some wear on the outer shoulder :)
Well said! I do have a "1.0G commute" though. But it's not lock-to-lock turning.
 

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Well said! I do have a "1.0G commute" though. But it's not lock-to-lock turning.
If you stay with the stock alignment setting and that is what it is now you will continue to get uneven wear. The Porsche's normally run a little more negative camber than most to improve turn in response and to make the tires lay flatter when pushed into the corners. The downside is wear on the inside shoulder. You can always run a little less negative front camber.
 

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Discussion Starter #11
Thanks, Jim. Recent input suggests they weren't too unevenly worn; the other grooves were close behind. I just dropped off the car at a highly-regarded alignment shop to get my new PS4S mounted (drop shipped from TR) and I had a conversation with the owner about all this, including the key points about my very spirited daily commute. He's going to check the alignment set-up and advise. I don't know whether the car is set up on stock settings or something else by previous owner/lease. If it's not stock, we'll discuss. Otherwise we'll leave it.

I'll report back in a day or so.

I'm excited to have new rubber, esp. the latest, greatest from Michelin.
 

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My front has a lot of neg camber -2.6* and tire wear was generally very even. I hit a pothole here in the golden state and it loosened things up. All of a sudden I was wearing the inner shoulders rapidly. The pothole jolt induced toe out and that was causing the uneven wear. All fixed now but my wallet feels lighter somehow...
 

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Discussion Starter #13 (Edited)
My front has a lot of neg camber -2.6* and tire wear was generally very even. I hit a pothole here in the golden state and it loosened things up. All of a sudden I was wearing the inner shoulders rapidly. The pothole jolt induced toe out and that was causing the uneven wear. All fixed now but my wallet feels lighter somehow...
Bingo, basically!

My alignment was off in a few places, and Toe was wacky: asymmetric and backwards. I don't have the experience to know how important the small errors were, but the toe seems significant. I'm not sure how I'll feel it in concert with new tires (probably less quick turning for both reasons) but I'm very happy to have addressed a tire-wear problem at the time of new PS4S. They wrote my (twisty) commute highway down in the box to describe my driving... :) I should have attached a photo of the G meter.

Front
Toe (L/R/Now): 0",-1/32",+1/32"
Camber: -0.6,-0.8,-0.6


Rear
Camber: L/R/Now -1.6,-1.6,-1.5
Toe: 1/8",1/16", 1/16"
 

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Yep, toe out will cause inside corner wear. As to your commute... spiriting driving is OK, but public roads are not a DE and you should never intentionally be pulling anywhere close to 1G, please keep that on the track.
 
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