I did some testing on my own server with my race setup. I conclude with the following: Tires have no effect (S,M,H), they all increase in temperature pretty likewise. The grip also seem to have no effect. Tried 97%, 98%, 100% and 90%. The track temperature has a bit of effect, I managed to get my tires too hot (105C) after 5 laps instead of just 4 when I lowered the track to 14C instead of 26C. Minor changes to track temp has no effect. I conclude that if there is nothing wrong with the mod then I need to learn how to careful driving this thing and not just hit the max throttle after every turn.