I ave a set on bridgestone RE11As that are less then a month old. I just noticed the other day a circumfrential cut on the sidewall of one tire. Its on the left steer tire. The cut runs almost half the circumference of the tire. Its fairly deep. In one pic I put my pocket screw driver in the deepest part to show how deep it goes. The cut is clean and smooth. You can see it just above the "potenza" and right below the shoulder blocks.
My question/concern is, is it safe to track on this tire. I have a couple autox coming up and then a HPDE at gingerman raceway in july. Gingerman is mostly right handers so this tire will be under heavy stress.

 

Appears you may be rubbing the fender. Depending on your ride height it may be happening on full compression, especially when entering steep entryways.

 

Def not rubbing. No other rub marks on that tire or any tires. Also the cut is sideways into the tire from the sidewal. Horizontally as opposed to vertical cuts as typical fender cuts. Literally impossible for the fender to cut into the tire that way.

Car is lowered with about 1 1/2 finger gap all around.

 

I wouldn't track on that.

You're life is probably worth more than the few hundred bucks it would cost to replace the tire.

 

Yeah that doesn't look like the fender since I can see most of your fender liner and usually its not that long of a cut or that clean. It looks like the tread is separating from the tire. Where did you buy them from? Seems like you should be able to get a replacement since it looks like a defect.

 

I wouldn’t trust that tire on street let alone competition. Strange, it almost looks like someone took a box cutter or sharp knife to it.

 

Guy I bought it (new) from is busy and out of town. I figure tire forum would give me better idea if tire is safe until he gets back. I figure its ok for normak street driving but traxking on it would be iffy.
I'm kinda leaning towards autoxing on it just to get the feeling of a tire blow out at speed. I use autox to better myself as a driver instead of competing with others. Autox would be the most safe enviroent to experience a blowout.

 

Unless its not safe on the street and the blowout doesn't happen when you expect it to.

 

looks like a tire defect. see if the manufacturer will cover it. (ie. visit a firestone)

 

The spot where the screwdriver is at is 7/32 deep. Measured with tire tread depth guage