Bill Lehman

Your last alignment increased rear toe, this is worse from a wear standpoint and would be slower on the track.

Macster

IIRC (my references are not handy) rear toe wants to be 5' +/- 5' per side with a max. difference of 10'.

If my conversion math is right the car now has way too much rear toe and the toe difference is way out.

5' is 0.083 decimal degrees and the car has 27' in one wheel and 13.8' in the other. (13' is GT2 territory.)

If I'm right the alignment is worse now than it was and it wasn't right then.

Jim Michaels

I agree with Macster and Bill. The new alignment toe-in is too much on each side, and side-to-side toe difference is also too great. The rear toe spec range for my '06 CS is .00 to .17 per side, so the midpoint of the spec range is about .08. The total toe spec range is .00 to .33 (midpoint about .16), with a thrust angle very close to zero. [My toe-in is .09, total toe is .18, and thrust angle is -.01] Your car's previous toe-in, total toe, and thrust angle were much better; and fully within the spec range. A little rear toe-in helps to settle the rear-end down, but the amount your car has now goes overboard with that, and should produce excessive tire wear.

We haven't mentioned the camber measures because they have remained within spec and look normal. Depending on usage and how much front camber they have, some may like a little less than -1.7 in the rear, and some may like a little more. Anyway, -1.7 or -1.8 is fine for most (mine is -1.8).

fhp911

I have 20k miles on my '11 Boxster S, with probably 12K of that on the street [the rest on the track with track tires mounted.]

My street tires -- front and rear -- still have a good bit of tread left.

I have to agree with the many posts here that suspect your alignment is off. 1 track day [I also had 1 track day on my stock tires] can't be the culprit -- and you've worn out your tires much too soon. Faulty alignment is the likely cause.

Fred

Tommy 5

Thanks for your replies, guys!

I'm regularly getting at least 600km (+/- 372 miles) out of a tank of gas with about 10 liters (+/-2 US gallons) left, so I don't think I'm driving the car too hard. I'm thinking the rapid tire wear has more to do with the alignment; and based on all of your responses, my initial hunch seems to be correct. Especially in light of the current alignment specs.

I am putting the car in winter storage this weekend. When I take the car out of storage next spring, I'll put new tires on and get another alignment.

In the meantime I'll be pining for spring!

Tommy

Jim Michaels

Tommy: If you got excessive tire wear with your old alignment specs, I don't think the alignment was the problem. I suspect that your current alignment toe-in will cause excessive wear, however.