I'll be taking my S to the track, 20000kms on my car with stock tranny and diff fluids...can I race with stock fluids or should I at least go MT90 and 75/90?

I won't be pushing the car too hard as I'm keeping stock brakes and pads anyway, maybe 3 hard laps and 1 easy...
Anyway, any input will be appreciated! Thanks.

 

stock fluids are fine. the only fluid you need to worry about is the brake fluid. change it out to something like Motul 600 or ATE Superblue. or else, if you are hard on the brakes, or you like to use the brakes, then the fluid will boil up and you'll get "mush".

 

Thanks Schatten.
I was just a little paranoid after reading all those posts about how weak our diffs are, and all those people who had broken their trannys...

 

Listen to the brake fluid advice. I went out with stock brake fluid, and boiled it in a short time of spirited track time. After that you end up with mushy brakes and a not fun track day thereafter.