For those that track their daily driver using their every-day tires, what are your criteria for when you replace your tires? And how many track days do you go generally before replacing a set. Just curious as to what rules people generally use to decide their tracked daily driver tires are toast.

 

I'm on my fourth complete set of tires since March mixed tracks and hill climbs, some of it serious, some of it fun.

(1) If they go off - basically they can look ok in terms of tread depth but have no grip left e.g. cooked too many times (I can see this by looking at long and lat gs and by feel obviously).

(2) Damage to tire - particularly outer edge and sidewall

(3) Puncture - I won't run on a plugged tire.

(4) significant differential wear (can be dependant on circuits e.g. right hand circuits will put a lot, lot more wear on the outers of the left hand side. Keep a beady eye on the inner sides of fonts and rears.

(5) Loss of grip on wet roads (whilst driving normally) - I use my cars in GT fashion (Im over trailers and flat bed trucks )

You can get the MPSC2 N1 tires (now) - I find them both very good on the road and at the track (tire noise doesn't bother me).

 

My experience with my 911-C2's using several sets of dedicated SC2's was that tires were pretty much cooked around 36 heat cycles. Plenty of tread left, just wouldn't stick anymore.

 

First the tire itself, the Michelin Pilot Sport 4S is a great starter tire and good in the rain, the Sport Cup 2 would be the next step up in performance. Both of those tires are good daily drivers.

Second is tire wear. You're going to find that this varies widely. When you first start out you will be harder on brakes, then as you get better you will brake less but will be harder on the tires. BTW - tires are much more expensive than brake pads

Third is the track itself. Track grip is inversely proportional to tire life. So if you get a little slide, or are driving in the wet, your tires will last longer. A track with a monster grip surface will be similar to a cheese grader on your tires.

So what's the answer? I push my car hard in the advanced run groups and get 9-11 track days on a gentle track and 5-6 days on an aggressive/grippy track. I've logged over 40 track days so far this year (with a few more to go) and consumables are killing me.

 

Negative camber plays a role here too:
Track usage at stock camber setting will tend to destroy/overcook the outside edges of your street tires very quickly. More negative camber helps prolong tires life on the track, but has the opposite effect on the street (because of increase wear on the inner edge of the tire).

It pays to find the correct compromise for your individual usage. At some point if you track enough it becomes cheaper to buy a 2nd set of wheels and put R-compounds on them for the track, then switch back to your street-tire wheels for everyday use. In that format, your street tires last essentially forever (by car guy standards) and you only have to worry about replacing the track tires as needed.

 

I did 15 track days this season at 6 different tracks on one set of Michelin PS4S. They seem to be wearing evenly and still have pretty good grip. This is w the front camber maxed out at about -1.4 or -1.5. I'm not exactly sure if street tire compounds heat cycle out like the R-Comps, but I guess I'll find out next season. Some people think they do, some don't.

I think in general the idea is you could run them down as long as you are happy w the grip, and they look reasonably OK upon visual inspection. Some tracks do have tire facilities near by or at the track, so if you happen to wear them to cords you could probably get a new set there so that you can get back home.