Originally Posted by PERRYinLA

It's sad only in that it was totally avoidable if the tire wear had been monitored and the tire was flipped at the right time to even out the wear as much as possible. Even with alignment within specs, many of us (and not just SCs) have this same inner wear problem on all 4 wheels, so you gotta flip if you want the most wear out of your tires.

I've done this on my past two sets of tires. Tito at Atlantic Tire on Fairfax (for those of you in LA, he's at 323.654.0814) flipped all 4 of my 16" tires for only $40, and I got thousands more miles of life out of my tires. You can see in the pic below that I waited a bit too long for that particular tire, but I wanted to get all 4 flips over with at the same time.

For the tire shown above, it looks like flipping at any point in the life of the tire would have helped out, but usually it's best to flip at the correct "halfway" point so that tire life is maximized, i.e.: both edges wear down to the 2/32" T.W.I.'s at the same time.

(On most tires, the last 2/32" of tread depth is not usable. And most new tires start with 10/32" or 11/32" of tread depth. So you are usually working with 8/32" or 9/32" of tread that wears over the life of the tire.)

As I explained in the following thread:

https://www.clublexus.com/forums/sho...d.php?t=185290

... the optimal time to flip is when the sum of:

the usable tread left on the inside edge
+ the usable tread left on the outside edge
==================================
equals the total usable tread the tire had when new

If you flip it before that point, the original outside edge (which ends up being inside) will wear out before the rest of the tire.
And if you flip it after that point, the original inside edge (which ends up being outside) will wear out before the rest of the tire.

But if you use the summation method, both edges of the tire will wear out at the same time.