That I can't answer. Try calling both of them. You can find their contact info at www.sheptrans.com and www.teamrip.com

 

The issue is that they don't protect the gears as much as they should, they feel great but thats because they are thin and allow for smooth shifting...

 

i use BG II, which was recommended to me by jon of TRE. My first transmission, i was told that tolerances werent to spec from the factory, according to TRE

 

The fact that you are running 550+ WTQ might have a lot to do with your tranny going bad than the tranny fluid. I honestly don't think the EVO tranny was designed to put down that kind of power. The less viscous the fluid the better it is for your synchros but the worse it if for your gears, as a result gear wear will increase but shifting will be smoother. On the other hand thicker fluid may provide more protection for you gears but slow down sychro performance (notchy shifting). Synthetic fluids will provide a little more protection as the are slightly more slippery. I honestly believe the stock fluid provides the best in terms of shifting performance and gear longevity ....

The 6 speed holds slightly less fluid compared to the 5 speed and it is designed in such a way that there are risks of overheating if the incorrect type of fluid is used.

 

shep ftw.

 

I'm almost at 40,000 miles, I've been using BG I since 15,000 and changed it to BG I again at 30,000... so far so good, switching over to BG II at 40,000 as recommended by TRE and is what the dealership uses on 5spds.

 

I am not blaming my tranny falling completely on the fluid but it definitely had a part in as to why it went out so fast...

 

so in summary...
Redline MT 90 - as Per John from Shepherd Racing
AmsOil 95w Gear Oil - good brand but not too many evo testimonials
Royal Purple - good brand but not too many evo testimonials
BG Syncroshift II - lasts longer than Pennzoil/GM?
Pennzoil/GM Syncromesh - good but can be too thin or not last very long

anyone here more about amsoil and royal purple???

 

i use the Diaqueen 75w-90 6speed gear oil in my 5 speed. Shifts as good as Syncromesh. Syncromesh makes me nervous. I mean its not even API GL-4 rated...........Matter of fact, on the bottle, its not rated anything!!!!! MT-90 is at least gl-4......Ray

 

It is rated GL-S. I would highly recommend anyone using Pennzoil Synchromesh to replace their tranny fluid often (every other oil change) as the fluid degrades a faster than others. If racing on a track, I would highly recommend changing it with something more viscous as added protection. My 2C ...

 

300+whp since 10K( according to my traps )
Used 2 BG's and 1 Redline lightweight shockproof since 5K in my trans.
Changed every 15K. Got 50K now and no problems.

I aggree that GM syncromesh is thinner than BG.
I used GM syncromesh before switching to BG and it grinded every time I tried shifting fast (3-4). AMS recommended 2 BG's and 1 redline for my power level and the grind was gone.
Oh...stopped by my local Mitsu dealer and parts were stocking up on BG's.
.

 

I think you're mistaking Super DiaQueen (GL-4 for the trans) for DiaQueen (GL-5 for the diffs). The trans fluid costs about $80 at Mitsubishiparts.net, and the diff fluid costs $35.

 

I preffer OEM better then anyone

 

I have used Royal Purple and I hated it. Even in warm weather it felt like shifting through frozen pudding. Imagine how thick it was in cold temps! I use nothing but Royal Purple in my engine but I'll never use it in my trans again.

 

I went down the road and talked to the guys up at forced performance and they recommended me using the Royal Purple Synchromax. I have almost 70k on it now and is still shifting great. I am guessing it is notchy shifting cuz of how thick it is....