New TSB from Mazda Australia says mineral oils only!
 

Well, I didn't believe it either :scratchhe

But here it is -- hot off the press, July 06, saying unequivocally "Synthetic oils are prohibited in all Mazda rotary engines including Renesis in RX-8. Only mineral oils must be used." :Eyecrazy:

Many, many questions are raised about engine longevity for early buyers from this, it seems to me.

Oh, and please don't shoot the messenger :hahano:

hmm, they claim it's due to carbon deposits. But we all know how best to get rid of that :)

YES WE DO! In fact I will be spending this Fri, Sat, Sun removing deposits at this special carbon removal facility :)

I am glad to see that TSB.... thanks. It clears up two points:
1st) 5W-30 is ok to us
2nd) Only Minerial Oil.....

which is great for me because that is all that I have used.

that TSB is hilarious, synthetics don't eat seals, at least not since the 70s.

As for carbon deposits, synthetics burn cleaner, so good luck with that. I can't believe they are trying to prepetuate that crap.

One less excuse for people to substaniate their waste of money buying syns for the rotary. Still some will profess it's all a conspiracy :suspect: and never believe any of it...

depending on what those O-rings are made from.... If they are just rubber like most o-rings are, syth wont hurt them. Alot of turbo's have o-rings in them and you dont see those getting eat'n up from synth oil.

I'll stick to what mazda says and keep using the suggested for now.

The TSB mentions seals with regards to pre-renesis engines. For the RX-8 the only thing they mention is carbon buildup...


So if anything, this will help us move on with the debate on syn vs non-syn because the single reason mazda is giving us for not using syn in the 8 is a non issue.

Once again we see another piece of cover our ass marketing. First of all as has been proven time and time again, synthetics do not leave worse carbon deposits than synthetics. Quite the opposite actually. Most of the carbon deposits in an engine come from the fuel used anyways. Maybe we should stop using gasoline! That would at least make some people happy.

As has also been stated time and time again, the original issue in the past with synthetics was from some synthetics, specifically Group IV PAO's. They had issues with dissolving rubber parts in an engine such as seals. This is what Mazda is pointing out. This goes back to the statement that Yamaguchi-san said to me last year at Sevenstock. "Not all synthetic oils are created equal". Most today are formulated to solve the issue of melting rubber parts. There were 2 ways they could do this. One way which was the easiest was to add an additive which neutralized the chemical interaction between the PAO and the rubber. The other way was to just modify the PAO during formulation so the property was built in. Either way worked to cure the issue.

Idemitsu synthetic "rotary safe" oil is a Group IV PAO. Remember this is the group that had the issues. Guess what they did? They modified the formulation so it wouldn't affect rubber parts! Oh happy days! There is a remote possibility that there is still a synthetic oil on the market that has not taken the steps necessary to cure the issue. Fortunately most have and the most popular ones are included. Royal Purple and many others are fine. Remember that not all synthetic oils are Group IV. some are Group V. They would not suffer any issues. I have been running RP, a Group IV oil for years now in a rotary with no issues. so have many people including Racing Beat. Even Mazda races their engines with Group IV oils. If there is any synthetic oil anywhere in the world that does not have the necessary formulation steps taken, they could be responsible for this TSB. Different parts of the world get different oils and formulations just like they get different gasolines.

This all goes back to the fact that Mazda isn't going to name everyone who's oils are good and those few that still have issues so releasing a blanket statement to include everyone is the easy thing to do. This is the legal side of the company talking, who along with the financial side of the company shouldn't be influencing what gets said when it comes to technical topics they don't know about. Unfortunately with lawsuits the way they are now, this is necessary.

To the people here that have been using synthetics for a while, don't worry about it. Keep using them. You are fine. For the most part I only see people here running well known oils that are known to work good. A TSB isn't going to change that. The thing I feel sorry for is the people who can't seem to distinguish the truth from a legal statement made to keep giving dealerships bs reasons to keep voiding warranties. It's all about money. The more warranties they void, the less they spend.

Just out of curiosity, what octane of gas do you run?

:Eyecrazy: this just prove's one point for all! you can't win you can't lose you just take a chance like everyday driving and hope that rock won't find your bumper or windshield to make you pay out the behind for the repairs mazda won't cover for your had dollars of joy riding there product!! :spank:

more often than not 91, sometimes 93, occasionally 89 .. our gas also has 10% ethanol here

jk

and expo1, careful with that bumpy tunnel turn :ylsuper:

rotarygod makes some good points, i.e. synthethics are probably compatible with the renesis seals, but the TSB only mentions carbon buildup in regard to the renesis. It does not say anyhting regarding seals in the renesis. Based on this I think we should focus on the carbon builup issue primarily. I agree some synthetics are cleaner burning than mineral and so this would not make any sense. I suggest you all experiment with torching some oils and post results of your findings. For instance, redline10-40 virtually leaves any residue, however german castrol 0-30 which is touted in BITOG as one of the best group IV PAO's leaves an incredible amount of gunk and residue and alot more than castrol GTX in my experimentation upon torching a sample. I've found motorcraft semi-syn 5-20 leaves a little more residue than redline and castrol 5-20 GTX leaves a fair amount more residue than the motorcraft. So, I urge you all to post results and maybe we can get a quantitative analysis on this issue.

When Mazda Australia write me a letter telling me they'll void my warranty if they catch me putting synthetic in there, then I'll pay attention. It's a moot point with me......I've only ever used Mazda Rotary Oil.

I'd use synthetic if I found it convienient to do so.

I don't find the torch test to be too relevant to the issue. Here's why. This test is useful if we are trying to find out how many eposits our oils leave after they have completely burned off. Logic would say that this is relevant because we burn a small amount of oil in the engine. However it does not take into account the diference in burn characteristics and flash point when diluted with gasoline. Even a 2% dilution of oil with gas can result in a nearly 100 degree lowering of the flash point of the oil. This also includes what is in it. With oil injection we have such a large ratio of fuel to oil that flash point concerns are nearly moot.

Synthetics should only be judged based on their performance in the engine as a lubricant in the traditional fashion. If we let the oil burn off like this, it doesn't really matter which one you have anymore. Your engine is toast. Most of our carbon issues are with the fuel used. Piston engines which don't inject oil into the chambers still get carbon deposits in them so oil isn't the issue.

The TSB is a safety measure in the event that someone somewhere actually finds an oil that does happen to cause an issue. If carbon is really the issue, they should ban all motor oils and gasolines from entering the engine. Perhaps 2 stroke and ethanol?

I agree with fuel dilution lowering the flash and altering the burn, but that still doesn't alter the chemical makeup of the oil.

So rotarygod flash point aside, are you saying that if you take the worst oil with the most residue mix it with large fuel ratio then it will burn off all the deposits and leave no residue?

Quote from rotarygod: "This also includes what is in it. With oil injection we have such a large ratio of fuel to oil that flash point concerns are nearly moot."

I agree that the flash point is moot because synthetic will burn just as well as mineral with fuel dilution, but that still does not address the issue of carbon residue left after the burn. I think the sulfated ash of the oil will be the most important characteristic to consider at this point now that mazda has finally stated their issue with synthetics in the renesis. Particularly, that lower sulfated ash oils leave less carbon build up and that a significant amount of synthetics have a higher ash content than minerals.

Hell yeah!! Let's go way back and throw some Weber side drafts on there too. :)

I doubt your dealer would want to spend the money and time to do a chemical oil analysis just to see if you are running synthetic.

API Certified For Gasoline Engines and/or API Service SL----those are the only requirements for engine oils used in RX-8s.Unless Mazda send out a revision to the Owners Manual superceding those requirements your warranty is in tact FULL STOP.

I would point out this is an Australian-sourced TSB, so 5W-30 may not be totally appropriate for you elsewhere in the world, depending on climatic conditions.

Correct.

Oh NO !

my balls are shaking ! Shake it BABY !

Synth .... I changed to RP 5w30 .... couldnt be happier ! Oh yes Full Synth all the WAY.

This letter .... is totally a cover my ass kind of company TSB.

Mazda just "ignored" 8's survey cuz it "lowers" their "overall" score. Is that cover my ass kind of PR speech ? I think so.

This TSB, I think its just the same idea.

hell if ur worried about carbon deposits buildin up, TSB or not from mazda from australia....... just go to ur local auto store.......pick up some intake system cleaner........which removes carbon deposits......( IF U DRIVE LIKE A GRANDMA AT LOW RPMS EVERYWHERE) becuz gas it too expensive to go fast...........then run the synthetic n buy that intake system cleaner every 10-20k miles, n ull be carbon free lol

Rotarygod you are my hero!
Two more thoughts:
1.Here in Europe the original 5w-30 Mazda oil (which is recommended for the Renesis) is synthetic. So, is there any question?
2. I hardly believe, that a true mineral oil can reach the 5w spec., maybe 15w.