i know that coders have not many time but i post this because i will forgot about this idea
we have refueling in pitstop already... when you have low % of fuel, you drive to pit, yes?
what about tires? if you drive to pit lane too late, your tires will be damaged
but tires shouldn't be changed at same time as refueling because it would be too boring
maybe if you have 50% of fuel, tires have 75% or sth like that
you wait enough long for refueling and changing tires should quick so you can wait longer for fuel after or back to track with changed tires only