I thought that what the bars on the tire indicators were for. I've seen them go from full to almost half full, but didn't notice the number changing.It's the amount of wear on your tires. 10 being the least worn and 0 being completely worn out.
You have to be in an event with tire wear enabled. If you raced in an on line event, the host can choose to have tire wear enabled. You should then see the numbers go down as the race goes on.There as a number 10 next each tire down in the bottom left of the screen. As far as I've noticed it's always been a 10 in any car and they don't seem to change after a number a laps. What is it?