911s are usually pretty easy on the front tires. They usually last twice as long as the rears. That looks like a TOE out issue to me.

 

I would get your alignment checked and see at what it is at now, its been over 2 years and 10,000 miles.

 

Chuck, thanks for posting my docs. How can you tell if the numbers are toe in or toe out? Also, since I've got new tires, what are the best alignment specs for me to keep this from happening again?

 

Here's the other issue to consider, and I certainly hate asking such rudimentary questions... When you do an HPDE event, are you re-setting your tire pressures after the event? Also, as I mentioned earlier, I saw significant pressure increases during single sessions on street tires, especially during the summer when I started at 38PSI as suggested by a tirerack rep. I actually saw pressures in the 48PSI range on my PS Ribs. Driving a car at an HPDE event at those pressures could KILL tires in a hurry! Driving a car on the street at higher pressures with to much toe OUT would also do the same...

Mike

 

like everyone has said..either the toe is not set properly or your neg camber is to high..

 

ok..here we go...as you can see from the charts (the first chart is before alignment and shows -.58" total negative toe, which is toe OUT) the second chart shows +.12 total toe or positive toe, which is toe IN...in both cases negative camber is -1 degree or less...so it is definitely not a camber issue..either the toe has gone negative or it is an inflation issue as mentioned by others...