You are right, there are so many variables to cover! Perhaps there is no problem for most combinations. The format I like to use with AMS is the following. 60/90 mins practice 60 mins qualifying 30 minute race. 107% difficulty, medium aggression, unlimited tyres, tyre and fuel usage normal, track progression medium/normal I play with the F Vintage, F Retro and fabulous F1 71 mod and keep my races fairly brief as half an hour is plenty of time in which to make a mistake. The problem I have with my combination is that the fastest times of the weekend are set in practice or at the end of the race, and the slowest times in qualifying. Obviously the opposite is true.. I definitely do need to do more testing, I was happy with my findings but then some overly quick times appeared..