View Full Version : Royal Purple Synchromax

01-14-2009, 11:23 AM
I was wondering if this stuff is any good? Also, can it be used in a 6-speed manual tranny (B7 RS4)?

Thanks in advance!

01-16-2009, 07:29 AM

01-18-2009, 05:37 PM
Royal purple is the shit! only ever used in my vehicles and is the best!

01-20-2009, 06:40 AM
if the transmission oil is also lubricating the front differential i would use redline MT-90 as its designed to lubricate both differentials and gearboxes.

01-20-2009, 05:57 PM
It is..... What harm would the synchromax do to the front diff?

01-21-2009, 01:56 PM
ive heard that royal purple failed particular parts of the cold weather testing, I cant find the specific article, however when i red it, it made me switch to red line oil real quick.

01-22-2009, 01:46 PM
...just something to condsider...if you don't have any real reason to change the tranny fluid, why do it? I have a B6 A4...so the gearbox is different. I had the input shaft seal fail, put in some synchromesh (pennzoil) to suffice till I could put in some Redline but now wishing I didn't.

I used Mt-90 with some Shockproof (as I've read quite a few have done and like) and since I live in E NM which dosen't get real cold. Since doing this over 2 weeks ago my shifting is acutally harsher/harder to engage than the mix of factory/synchromesh filled to the correct levels. Since I just spent the $$ on the redline I'm trying to deal with it hoping it will get better but now wish I would have just left it since it is a "lifetime" fluid anyhow.

From what I've read on AZ most like Redline or Motul so my case maybe an isolated one. The motul is a bit more expensive, but wish I would have tried the Gear 300 instead of MT-90 or left it alone.

Also the Synchromax, synchromesh, synchroshift, etc, etc fluids are of a thinner weight than the spec'd 75w90 transmission fluid. If you compare the data sheets they are I'd say around a 20w motor oil where the 75w90 is more like a 10w40. Thinner should result in better shifting but sacrificing overall protection.

04-08-2009, 06:47 PM
just put in royal purple max gear 75w90 in my '01 A6 6 speed tranny and rear differential and it is much smoother when shifting gears. i bought it at autozone for $16 a quart.