Changing the oil in our cars is surprising easy, once you get the filter off for the first time. In fact, I would recommend taking your car to the dealer first, let them change it once, and then do it yourself from then on. Also, don’t forget to buy some crush washers to keep on hand for the oil pan drain plug. Oh and before I forget, I’m using there 5W-20, My car had 2,780 miles on it when I did my first change.

Ok, all that fun aside, so how is the Royal Purple? The engine is quieter at idle and while cruising at high speeds (almost silent), it still makes noise when you gun it but it’s a nice effect when cruising along at 70+mph. The engine appears to rev and fall (somewhat like a lighter flywheel) slightly faster, which makes rev matching easier. Can’t feel and power differences (not that I was really expecting too). Idle is somewhat smoother; I don’t feel as much vibration in the seat every few seconds as I did before. Overall, the differences aren’t as large as when I put this in my Mazda6 V6, but the nature of our engine is somewhat different. So is it worth the cost and trouble? Jury is still out on this one. The trany fluid was a much bigger difference in terms of feel and performance; however, if I notice an improvement in fuel economy I would say that would make it worth it. If your not comfortable running synthetic oil, I don’t think your missing much with the synthetic motor oil, but I would definitely swap the tranny fluid.

In addition, it should be notes that while I changed out about 4 qrts, there is still some other oil in my system, as the oil coolers hold, about 2 qrts? So I’ve have to do another change or two before I get it all out.

I’m hoping that this improves the fuel economy some, which I will monitor closely. I’ll also watch to see how quickly it burns down for me, and what kid of soot I’m getting on the exhaust tips.

If anyone else is running Royal Purple, I’d love to have them chime in with their thoughts.

I read an interesting article in a Rotary mag yesterday that states the oil pressure gauge in the 04' RX8 is only a sensing unit and does not really reflect actual oil pressure just that it is reading .8 psi or above.... can you believe that? they made it a glorified idiot light...!!

I wonder if there are any aftermarket kits to make my oil gauge a real gauge?

This is my first rotary even though I have always loved the idea of one. I can tell you that I do like mine. Even if it did entice me into a speeding ticket... my own stupidity...had the Bose going too loud to hear the detector... who says you have to be young to be stupid...

Brillo,

Thanks for the write up, I was thinking of going to RP at my first change. Keep us posted on the soot and mpg's. :)

Good write up. Any notion to change your differential & transmission oil to RP too ?

I read an interesting article in a Rotary mag yesterday that states the oil pressure gauge in the 04' RX8 is only a sensing unit and does not really reflect actual oil pressure just that it is reading .8 psi or above.... can you believe that? they made it a glorified idiot light...!! ...


This isn't surprising, and is quite common in OEM guages. They don't want owners in the service department whenever they thing something is wrong, over-reacting.

You can buy and install any number of aftermarket guages. The trick is placing the sensors, or sending units, in good locations.

I for one would be interested in an oil temp, and oil pressure guage. Eventually I'll probably add them. You'll probably find (with an aftermarket tach) that even the factory tach is innacurate/slow to respond. That's quite typical too for manufacturers.

In addition, it should be notes that while I changed out about 4 qrts, there is still some other oil in my system, as the oil coolers hold, about 2 qrts? So I’ve have to do another change or two before I get it all out.


Total oil capacity of the Renesis with dual oil coolers is around 7.6 quarts - an oil change only drains about half the total volume! (We first discussed this issue around September last year). It will take several changes to get to mostly RP.

Regards,
Gordon

I acutally did the Royal Purple Tranny and Diff fluid first about two weeks ago, been great, between the two, the tranny fluid is much more noticable.

This topic has held my interest ever since I was looking for a new rotary...
I have a good friend who deals in Amsoil and swears by it (and by the looks of his SVT Cobra, it shows!). But with the luck some have had so far w/ RP, I'd fear being the first to venture to Amsoil... :(

Brillo, any specific RP product #'s recommended for both the Oil and Tranny Fluid? Their site's application guide is somewhat confusing.

Isn't RB a synthetic oil?? I though you're not supposed to put synthetic into the rotary?!

75W-90 for both the tranny and diff. RP also makes a 5W-20 engine oil.

RotaryZZ, if you do a search there are a bunch of posts on the matter, if your not comfortable with the engine oil, just do the tranny/diff swap which IMO was a bigger improvement in drivability. There are no issues with the tranny/diff.

But I believe the official word from Mazda is still no synthetic for the engine, am I correct?

Actually I was talking to my service rep. at mazda the other day during an oil change and asked about synthetic. He said mazda sent out a letter and in their training for the rx-8 it says that if they find out that a customer has used synthetic through more than 2 oil changes their warranty is void. I don't know if he was just trying to scare me, but he has always been a reliable source of information for me.

But I do find it funny that I just saw a thread that Rosenthal is selling synthetic oil, and overstocked it because of so many requests.

While I understand your concern over the oil, I would rather not turn this thread into a synthetic vs dino oil debate. I did a ton of research, spoke with several long time rotary guru's a few tuner shops and the folks at Royal Purple before making my decision. Again, my overall impressions are favorable, but the improvements aren't as massive as the tranny and diff change, so if your worried about it, just use dino oil and go sythetic on everything else.

I sent the following email to Rosenthal and this was the content and response:

>I notice you sell Redline 5w20 Engine Oil in your maintenance section. Do
>you support the use of this product, or just sell it?


As with everything on our site that is non-factory, you use at your own risk.

I only started carrying it because RX-8 owners have asked for it.

I had no intentention of turning this into another synthetic debate I just wanted to state what I was told by my dealer.

I've been using Royal Purple 5w30 in the engine for quite awhile, 75w90 in the trans & diff. :p

It works great, the engine is smooth, burns a little less oil than dino. My trans shifts like silk and when idling with the car in netural the trans is quiet, compared to the stock gear oil, my diff hops a little less on kick ass starts so, I sleep well at night knowing I've given my 8 the best of care. :)

The motor oil is API, SL GF-3 rated, just what Mazda requires in a motor oil and the gear oil is GF-4 & GF-5 rated with a limited slip diff additive built into the oil.

Royal Purple is also recommended by Racing Beat and their engineers as being a good synthetic for the RX-8 and have dynoed the oil in a RX-8, only to be surprised to see that it actually gives more HP!! :eek:

So, take it from there...........Mike Z :cool:

3 times the price... I did that in my last car. Now I'm thinking Castrol Syntec is sounding really good at 2.50 a quart.

3 times the price... I did that in my last car. Now I'm thinking Castrol Syntec is sounding really good at 2.50 a quart.

I wouldn't use syntec, there really are only 3 true synthetics I trust, Royal Purple, Red Line and Amsoil. If cost is an issue I would just stick with good dino oil, which is fine.

What About Those Of Us With An A/T?
Does Royal Purple Make Anything For Us?

if your referring to your A/T tranny, then yes they do make a A/T fluid. just visit their web site.

Been running all RP (engine, diff, tranny) for 3k miles, 5467 total so far. No problems, smooth idle, smooth acceleration, much better than stock! Now I need a grounding kit.

Been running all RP (engine, diff, tranny) for 3k miles, 5467 total so far. No problems, smooth idle, smooth acceleration, much better than stock! Now I need a grounding kit.
And you know it's better than stock how? Stats on comparison?

Well, the idle smoothness increased from a stock value of 4.8los to 8.3los with RP.

Trust me dude, You can easily tell, the difference is that great when compared to stock! Anyone who has had any biological schooling can tell you that the human body is a precision instrument and capable of registering fairly subtle changes in environment(and then it adapts to them). My comment is purely subjective, but subjection has justification when based on prior expereince.

Example:

I smack you in the left knee with a baseball bat.

Then I ask you: "which one hurts more?, left or right?."

Can I have some stats on that?

Well, the idle smoothness increased from a stock value of 4.8los to 8.3los with RP.

Trust me dude, You can easily tell, the difference is that great when compared to stock! Anyone who has had any biological schooling can tell you that the human body is a precision instrument and capable of registering fairly subtle changes in environment(and then it adapts to them). My comment is purely subjective, but subjection has justification when based on prior expereince.

Example:

I smack you in the left knee with a baseball bat.

Then I ask you: "which one hurts more?, left or right?."

Can I have some stats on that?
:D Nice stats :D I'll watch out for my knee's next time (is your name Tonya Harding?) Fact is, you don't have much to prove RP is better, which is my point. Subjective reasoning is ok, but in the end dino oil changed at frequent intervals is cheaper and more effective than syn RP...sorry but I don't buy the RP marketing hype. Better $$ spent elsewhere.

the difference with the tranny fluids is night and day, I'll understand if you don't go with the motor oil but don't discount the tranny/diff..... best mod do so far

It's true. I didnt notice much of anyting with the engine oil, but the tranny/diff is VERY noticeable.

Brillo , How much oil does the diff and trany each take ?

I called RP and Mazda to ask about the tranny oil. I am running RP Max ATF in the auto trannies of both my 8 and my FD. RP 75W90 Max Gear in both rears. It works very well. Make sure you have a competent person do the swap as the torque converter in the AT can hold quite a bit of stock ATF and has to be power flushed. I had it done by Marlin Mazda here in Florida. At first they were freaked so they called Mazda and they were told that RP in rotary trannies in great! The manual tranny and the pumpkin are quite easy to do. I personally flushed with a bit of RP after it was empty, then overfilled and closed the plug real quick.(manual RX7). I had the AT done before at AAMCO but I was not happy with the way they flushed the converter so I went to have it redone at Mazda. I am too scared to run synthetic in the motor, so I change my stock oil & filter every 1500 miles instead. Car runs great

I think it takes about 3Q for both the tranny and diff in a manual tranny. The manual states the specs but that is from memory. The MTX can be done with the help of another person but you will need to buy a fluid pump for about $5-$10.

I just called a store about the RP 75W90 tranny fluid. I believe he said $119.95 for a 5 gallon bucket. It was either that or 199.95. I can't remember because I think my brain shut down after the 1.

I buy the 1QT bottles (need 3 for a manual setup) at 10 bucks a pop.

Just did the Red Line MT90 for my trans last week. I'm in Los Angeles and it turned colder- 49 to 53 degrees F- at night a couple nights ago. Shifter is sticky at startup and takes about 5 minutes to loosen up (at which point it performs real well). The original factory fluid was working great. It was not sticky like the MT90 during similar colder temps. I have only 150 miles on the MT90.

Should I expect it to become better in the cold as more miles are accumulated? Apparently, I'm not the only one who's experienced this with MT90. I'd like to know if any Royal Purple users have experienced sticky/notching shifting at startup when the outside temp is cold. I hope your answers will allay my fears. Worst case I'll do what StealthTL did and mix 50:50 MTL and MT90, as it gave him great improvement. If that doesn't work, I'll switch to Royal Purple. And if that doesn't work...I'll go screw myself.

Just a Royal Purple observation - seemed rather odd to me. I had an open bottle of Royal Purple 5W-20 in my cabinet with the top off (covered by a rag) for about 6 months. It was left over from my previous RX-8 engine - since I got the new engine, I've been running dino in it (about 16K miles now). I decided to switch back to RP today, and when I poured the open bottle in, lo and behold - it wasn't purple anymore! Looked just like regular motor oil. I feel gypped!

I guess there must be some additive they put in to make it purple that gets deactivated by long-term exposure to air. Purely there as a marketing gimmick (how else could you call it Royal Purple?) :)

^ lol :D: my previous oil was Idemitsu Racing 5W-40SL fully synthetic,then i changed it to Trust F2 RE Spec for Rotary 15W-50SL fully synthetic,but now i change it back to Idemitsu due to the cost :mdrmed:

They use a purple dye. I've seen the stuff since I've been there. It is very concentrated. It goes away very fast. It doesn't need to be purple. The color started out as a joke on the beginning back when the oil was formulated for private use and just stuck to this day, hence the name.

Would you happen to know if there was a technical reason they were using the dye? I can't imaging a developer of a synthetic product just adding some dye for the hell of it. Maybe the dye served some purpose during testing, and they just decided to keep it in the final product so they could give it the cool name.

As far as we saw, the dye didn't serve any purpose other than marketing. As much of a numbers person I am, I do forget sometimes the importance of marketing

You guys do the tranny and diff RP change yourselves?

I had a shop do it, but I've also changed it in person.

I had a shop do it, but I've also changed it in person.

check pm

beers :beer:

I just called a store about the RP 75W90 tranny fluid. I believe he said $119.95 for a 5 gallon bucket. It was either that or 199.95. I can't remember because I think my brain shut down after the 1.


why would you buy 5 gal of tranny fluid????

2 qt. per 30 k miles.... 4 qts to the gall...

you are commited to 300k miles... might be a bit much...

now 119 delivered for 5 gal of motor oil.... a good idea!

beers :beer: