Hey, i just got my S2000 about a month ago and i have never used synthetic oil of any high end oil of other fluids. I got royle purple oil from one6 motorsports it feels like my car likes it but i cant really tell so what is the best fluid for oil, trans, and diff ANd my car is an 03', N/A if that matters

 

Just go with Mobil 1 10w-30 for the oil.
ATE Super Blue Brake Fluid
Honda Manual Transmission Fluid
and diff fluid...not sure...

 

For the diff - I am going to switch to LE-1605 (formarly LE-607), which quite a few folks here use. See RR's (who is well respected around here) explaination of diff oils (also read the oil journals).
RR commentary- http://forums.s2ki.com/forums/index.php?s=&showtopic=185775
Oil Journals- https://www.s2ki.com/forums/index.php?showt...&#entry12038273

DYI Diff change
https://www.s2ki.com/forums/index.ph...ic=348700&st=0