Rotal

Ok I’m about to replace my Gear oil in my 1990 turbo trany and I don't known which one to go with Red Line or Royal Purple. First of all I never heard of Royal Purple until I had nothing to do and I just was browsing the RB site and found it there. Looks like they like it so much they suggest to put their synthetic oil into the engine, which as far as I know is not suggested even by Mazda (on the sticker under the hood it is saying mineral oil only). So which one should I go with??

Ryde _Or_Die

Either one is highly recommended for the tranny. As for synthetic oil, almost every single person here uses synthetic, many(most that I have talked to) castrol gtx, including myself.

fcturbo2

I just bought some 20/50 Castrol GTX oil today. My engine is freshly rebuilt and RB recommends using mineral but non of the stores i went to dont even sell mineral oil. SO along with syntetic i will be running 2 cylce oil aswell just to be on the safe side.

bingoboy

were talking about gear oil here bud.

redline is good stuff. i havent used royal purple in my FC so i cant say. i know mazdatrix recommends and sells Neo synth oil, but ive never used that either. maybe someone else can comment on that

Rotal

For your information Mineral motor oil is any motor oil, which is not synthetic, which makes Castrol GTX a mineral oil because it is not synthetic. The las time I was changing the oil which was Castrol GTXit it did not say anything on the bottle about being synthetic.

fastrotaries

redline or the purple it doesn't really matter. HOWEVER what does matter is the limited slip additive. Mazdacomp recommends the Ford additive. about $5 and comes in a small bottle.

nd4spd

Many racers use Red Line and swear by it. They make oil for both limited slips and for cars without. In doubt, call them, they are very helpful.