I've currently got Castrol Driveline (formally Syntrax) in my 6 speed box, mainly because of bad experience when using full synthetic (Syn-5) in my previous 99MY where it affected the synchro performance 4th to 5th
A fluid change will be due soon and I was wondering what experiences people have had using full synthetic in the 6 speed box. Am considering Millers CRX75/90 NT

JohnD

 

I have been using Millers CRX 75 90 nt for as long as I've had my STI newage. Been spot on.

 

+1

 

Redline Lightweight Shockproof, fit and forget. Smooth as you like I have it all my scoobs

 

I used Syntrax in my old my99 and it was great. Changed to Millers CRX 75 90 for 6 speed in STI...also great. Had Syntrax in STI for one service interval...seemed fine. Didn't really notice any change between them.

 

Have enough Syntrax for service in unopened bottles if anyone wants it...bought but not used for service.

 

I was just wondering if anyone might have experienced any loss of synchro performance when changing gear at high-ish revs, after changing to a full-synthetic oil?

JohnD