i have read some posts here and seems like theres one guy that actually tested the 0w30 in his s2000 and if i go on any other forum and ask people look at me funny like i asked a forbidden question... OEM FTW BRUH. honda knows better. if honda blah blah etc... no real answers. so far ive seen aftermarked transmission fluid perform better in the j series transmissions and b series transmissions. and personally seen benefits of using 0w30 instead of 5w30 in few cars with rod knock( that actually went away after switching to 0w30 synth) but in the case of s2000 it seems more complicated. many say that honda did it for a specific reason others say i think here that at the time s2000 was released they didnt have a better option in 5w30 so they went with the 10w30 due to the quality of oil but now theres teh full synth 0w30 it seems like amsoil is true synthetic and some mobil1 are also true synth but then i read that some later mobil1 is not true synth anymore and actually a blend of some [censored] i forgot what it was.. this one they sell at walmart is it still full synthetic or also a blend?