Can anyone explain me, how does this system works? I thought I know how, but after today's race, I am confused very much.
after 3 laps in pits:
If tire wear > 30% tire is not changed..
=> tire will last more then 6laps, right? (maybe even 7)

Thanks

Struggled with it a lot. As you say so, it should be.

But is it he average wear, maximum wear ? And wear goes faster if you drive hot spots etc... so hard to say.

Well.. I had this problem in race:
FO8 @ KY2:
Lap 38 or so I am going to pits. tire change is set to "wear > 30%" It changed only FR tire, so I thought OK, it should hold to the end of race (62 laps). In lap 51 remaining tires got cold ;( I hardly doubt they will last more then 10 laps. (and I though, great 70% I am off the water :schwitz But no.

Can anyone explain how it works? Thanks

It shows after how much tread wear it changes tires. Like if you set it to 50%, it will change it when the tire is 50% (or more) worn. But here comes the but. It doesn't mean that you will have another happy 50%. In the final ~10 minutes tires will cool down like ice, thus making you slide more -> more wear, so you wont be able to use it for it's full life. (if you do 20 laps with 50% wear, it's unlikely to get another 20 laps out of it, more likely 15)
I'd say that 10-15% below the optimal temperature is ok, but if it cools down more, it's time to change it. The wear - lap count relationship is not linear in this case.

Also, if you are going into pits make sure you change all your tires if you think it's gonna change even 1. Having used/new tires mixed really destroys the balance of the car.

Thank you RevengeR
I'll keep that in mind