Alright gang, I changed the trans oil on my 5MT 3 this weekend with Redline MT-90. All I can say is... It's like buttah! It is much smoother (always has been very smooth to me) in normal daytime temps, but really nice on the cooler mornings. The cold temp notchiness is practically gone!

I purchased 3 quarts of MT-90 at 3R in Englewood for $9.95 each. In the end it cost me about $40 (had to buy a 23 mm socket at Lowe's for 6 bucks) and an additional 15 minutes while doing my LOF.

I cannot recommend this enough for our Mazda manual boxes... [img]http://coloradomazdaclub.com/forums/style_emoticons/<#EMO_DIR#>/338567b8.gif[/img]

I changed my gear oil with royal purple 75 90 and then my gearbox went out. I cannot say it was the oil but after a long story Mazda had to replace my transmission just after i started with RP oil.

Mazda has not gotten back to me why the rx8 is allergic to Royal Purple or not but i would say stay away for now. At least until i talk with mazda again.

I use Red Line in my transmission as well as the wife's VUE. Works great. I'm coming up due for another flush on my car- that gets expensive when you're using Red Line. But I do-it-myself, so it's not as bad as it could be.

I have heard good things about Redline. I didn't know it would make a differance on cold mornings. I may have to try. Do they make one for a rear with an LSD as well. My car uses 80-90w in both.

<div class='quotetop'>QUOTE (Sleepy Buffalo @ Nov 5 2007, 09:25 PM) [url=index.php?act=findpost&pid=9598]<{POST_SNAPBACK}>[/url]</div>

I changed my gear oil with royal purple 75 90 and then my gearbox went out. I cannot say it was the oil but after a long story Mazda had to replace my transmission just after i started with RP oil.

Mazda has not gotten back to me why the rx8 is allergic to Royal Purple or not but i would say stay away for now. At least until i talk with mazda again.[/b]

IS Royal Purple Syn. because thats what i used in my 88 626 and I have no prob. But if its syn. sometime you have to get all the old fluid out and i mean all of it. I took my tranny down to a tranny shop for it to be flushed with a computer so I knew It had nothing left. And then i put the royal purple in it and it was fine. ( mobile 1 is better in my op.)

You should be able to mix conventional and synthetic oils without problem. Unless Royal Purple is completely different.....

I was told by a mech. And a pretty good friend of mine that happends to be a pro tuner not to do that

Originally posted by Crm
I was told by a mech. And a pretty good friend of mine that happends to be a pro tuner not to do that

It's probably similar to one of those age-old "you have to change your oil every 3000 mile" myths that has continued to run rampant even though oil and engines have improved by leaps and bounds from our grandfather's engines.

Originally posted by Royal Purple website
[b]Are Royal Purple lubricants compatible with other motor oils? Yes. Royal Purple lubricants are fully compatible with mineral or synthetic oils. No special procedures are necessary when switching to Royal Purple.[/b]

Taken from:
http://www.royalpurple.com/rp-faqs-wu.html

I just got a new transmission in about 1000 miles ago, so i wound be trading it out for anything soon. However i will be using Redline instead of RP. And yes it was a syn.

Doesn't matter what kind of oil you use, it's still gonna get dirty, even if the viscosity is ok dirt will kill your engine faster than anything. I have a friend who is on a nascar truck crew that told me they lost an engine due the synthetic oil they used. Sent the engine to a lab to find the cause of failure. Lab said dirty oil, and it was royal purple, fresh before the race. People forget that mineral oil and syn had different properties, but both are a film of oil protecting metal parts. It's not typically good to switch from mineral to syn because syn uses a thinner film and tolerances can be tight enough that the film thicknesss can cause a failure. If your parts brok in on mineral it's safer to stay with it, unless the manufacturer designed it to break in on mineral and to be driven on syn. OH GOD this is an ugly can of worms!

^^I think that's another myth.

I switched a car to synthetic after about 125,000 miles on dyno oil. No leaks, no engine failures. The car was even run really low on dyno oil one day- took almost 3 qts to fill it back up (4 qt system). And when it was on synthetic oil, it saw and sat on the rev limiter on multiple occassions. Never an issue.

I had a V8 motor built and was told to beak it mineral and switch to synthetic after 500 miles.

Don't know about you guys, but I don't want to put anything artificially colored "purple" into my engine. Someone stated on another board that Royal Purple is a very good synthetic oil, but tends to clog passages after extended usage.

Redline MT-90 FTW! After installing the STS I noticed that while my shifts were indeed shorter you do lose a lot of leverage. It was especially bad on very cold mornings when the transmission is stiff and notchy. Felt like i was rowing a boat just moving through the gears. After flushing and refilling with the Redline the shifts are once again smooth and effortless, just slides right into gear. The difference on cold mornings is HUGE vs the stock fluid. Like everyone has said its a bit pricey but well worth it!

before the car was burned i switched over to redline i like it, and i just did my vw with redline also