I bought a used set of 18" wheels today with used 285/30/18 Kumho V710s (for autocross). The seller is a local ford dealer owner and I considered him to be a trustworthy guy. He told me that he thought I could get 2 auto x seasons on them and their previous use consisted of 4 qualifying laps and 2 autocross events.

Now these tires start with 4/32" of tread depth. I'd say the current depth is between 1/32 and 2/32.

How do I know when these tires are to worn to use anymore? I'm starting to get concered that these are more worn than he led to to believe. I have no previous experience with these tires, either knowing what is worn out and what isn't, and how fast wear proceeds.

 

If they are down to 2/32 you might get 1 season out of them. You can use V710s till they chord but at that point there performance will significantly drop off. Either way at 2/32 or 1/32 they are not as fast as there were when they were new. I have never run on a Hoosier A6 but I have heard that a V710's performance will drop off a little slower then an A6.

 

Hmm, well if I can get one season that will be ok I suppose. I'm totally new to R-comps so I won't be pushing them to their limit and as such they should last a little longer than normal.

 

R-comps take a whole new level of trust coming from street tires. This is my first full season on R-comps and I honestly think it took me at least 3-4 events to learn to trust what my tires can do. If you got them at a good price, I would use them as learning tires for sure.

 

I talked to the seller today and he returned some of my money after I told him I thought the tires were fairly worn.

Yes I think I won't be able to exploit them fully for some time. I'm coming from stock pirellis.

 

Last weekends autocrossing was awesome even with these worn R-compounds. The horrible understeer was gone, the lateral grip was high, the turn-in was crisp and she stopped on a dime. I moved up the standings significantly. The bad news is, there is only 2 events left this year.

This experience made it clear how futile autocrossing a mustang on street tires is.