I generally race OMP to gain around 10-12 GC per week, as to go higher than this is usually thwarted by hackers, even with FU cars.
However, there are tracks I like to race on, and tracks I avoid. In order to plan when to race I've compiled a list of the tracks, with their order of rotation, as I could not find this info anywhere else... and in case others may find it useful I've listed it here:
OMP schedule:
Day 1: Suzuka (East); Le Mans; Melbourne
Day 2: Hockenheim (National); Dubai (Club); Bugatti
Day 3: Berlin; Red Bull Ring (GP); Porsche (short)
Day 4: Monza (GP); CotA (National), Laguna Seca
Day 5: Mount Panorama, Spa, Catalunya (National)
Day 6: Bugatti, Nurburgring (sprint), Dubai (international)
Day 7: Hockenheim (short); Suzuka (West); RedBull Ring (sudschleife)
Day 8: Berlin, Melbourne, Monza (junior)
Day 9: Porsche (long), Dubai (National), Spa
Day 10: CotA (GP); Laguna Seca, Le Mans
Day 11: Catalunya (Club); Mount Panorama; Nurburgring (Mullenbachschleife)
Day 12: Suzuka (GP); RedBull Ring (GP); Hockenheim (GP)
Day 13: Laguna Seca, Monza (GP), Dubai (GP)
Day 14: Spa, New York, Bugatti
Day 15: CotA (National), Mount Panorama; Porsche (long)
Day 16: Hong Kong; RedBull (sudschleife); Hockenheim (short)
Day 17: Nurburgring (GP); Monza (junior); Catalunya (GP)
(For newer players, this is the 17 day rolling rota, so the new OMP weekly schedule just starts off where the preceding one ended.. so 'Day 1" is not necessarily the start of the new weekly tournament)