So, after 27 months (40,000 miles) I got bored today & decided to replace the Achilles ATR Sports that I had on the front of the 07. They still had 3-4 32nds left in the middle of the tire & 2 or so on the outer treads.
They were starting to make a little noise.

I replaced them with the same tire. After paying for the mount & balance at NTB....the guy said let me show you something......we went into the garage & the inner sidewalls of both tires had multiple big long splits...my life kinda flashed before my eyes. I had taken the car up to 120+ a few times with these tires..hit about 100 several times / week.....

Any idea why the inner sidewalls would split with zero evidence on the outer sidewalls?

Maybe I'll just run this second set 35,000 miles ....& keep my eye on the inside walls.