I bought a spare set of wheels for my FD that have Michelin Pilot XGTs with about 80% tread. They have a little bit of dry rot cracking, but aren't too bad. I'd guess they're 3 years old at the most.

This year I'm slated to do my first autocross events and maybe a driving school at Summit point.

Will the dry rot affect safety? How badly might the traction suffer? (Suffer compared to a newer set of the same street tires, of course).

Dave

 

They should most likely be safe enough but if you're seeing "checking" in the rubber due to dry rot you can be certain they won't have as much grip as fresher tires.

 

To me dry rot is a no go on any tire. Water seaps into the cracks wicks through the belts and separates the belts and the rubber. Your asking for a side wall blow out on a day of racing. When your car is teched they should be checking for dry rot, if they find it you may not pass inspection.

 

What I'm looking at is small, shallow cracks in the bottoms of the tread grooves. No checkering on the sidewalls. Whether it's actual dry rot or not, I don't really know. When I get home I'll see if I can get a good macro photo of it.

I will mention it to tech and see what they say - if I need new tires, so be it.

Thanks guys.

Dave