Everyone is always saying to use synthetic in these transmissions... I've been using swepco in my wrx for about a year now and the stuff works great. Its non-synthetic 80-90 industrial quality gear oil, it exceeds the GL5 specs.. So i was thinking of putting it in my RX7, but then i keep reading so much about how well synthetic does.. What do you guys think? Its 35 bux a gallon and thats about the same as what you can get amsoil for so...

 

I say screw the petroleum based oil for the tranny and spend the extra bling bling for a QUALITY oil like Amsoil. You'll shift smoother, quiet up those synchros and wish you would have done it earlier.

Alot of other people in here are also running a comperable Redline oil which im assuming people are going to suggest also.

 

Yes but this is quality oil and about the same price as synthetic. My mechanic swares be the stuff. He found out about it from a customer who brought his tranny in.. He was first puzzled by the blue oil, then when he took it apart the tranny was absoultly spotless the cleanest transmission he's ever seen..

 

shouldnt a true synthetic like amsoil always outperform anthing made from refined crude oil?