My best friend has a '04 STI. He put some Mobil 1 synthetic oil into his transmission. the guy is going crazy, he has heard all sort of rummors about the synthetic being too thin and well now he is telling me he is grinding the gears unexpectedly.
so, what is the best regular dyno (non-synthetic) oil for the STI's gears?
i gotta help him out other wise he wont let me ride in it anymore. :icon16:

Why did he change the transmission oil?
Did he put engine oil or transmission oil in the tranny?
He's grinding gears because he's shifting badly, not because of the oil viscosity.

He changed the oil cause it was time to change it, obviously he used tranny oil. the oil is synthetic though and it is too thin according to a few guys who own STIs. so he just wanted to know which would be the better oil for the tranny.
shifting badly? wtf? he's a good driver he just put the wrong choice in there.
so which oil would you recomend?

redline works the best by far