Cumulative Synthetic Oil Discussion
 

Yes, i've read the thread about synthetic oil vs. regular oil... and i do own an rx7 Efini so i know how rotary engine works... ;)


the manual for the 8 mentioned:

"Recommendation oil [Pure-Motor-oil golden SJ]
API SJ/ILSAC GF-2,SAE 10W-30"

am just wondering what does this mean? can the rx8 use synthetic oil now? i know MS/Dino/Mobil1 works for rotary engine but how about other brand?

any input would be great... tanx in advance...


-D-

Re: oil for the rx8...
 

:eek:

whaaaaat?? the owner's manual??

yup yup... funny?? :D
EASTMOON one of our forum member in JAPAN.. hehehe got his rx8 allready... ;) so for expert out there what does it really mean?

ohhhhhhh, yeah i knew he had one, i thought that you did too!! :D ahahaha... never mind :)

no problem dude... ;) like some members have said... "he's one lucky bastard!!" hehehe

So from what I understand, rotaries eat up oil, its part of their function; not a lot, but more than a piston engine. With understanding that, isn't the purest, cleanest oil what should be used for the Renesis or is that not as important as the grade?

unless you're buying used oil (as no one does) than any oil is "clean and pure" as you put (clear of "contaminants" to an acceptible level), even the cheapest kinds.

what is really key is the combustability of the oil: if it can really just burn up nice, quick, and clean (like lighter mineral oils do), then it is better suited than an oil which doesn't burn quite so well, and cokes up the seals (like a heavy, burn-resistant (which would be a bad characteristic in any motor) synthetic or something).
that is the talking point: will synthetic burn off as nicely as a mineral oil?? and secondly, is the synthetic (being consumed at a constant rate) worth all that extra money for the protection it offers to this engine?? (although that's a different discussion)

From my technical understanding: The "conventional" Wankel had the intake/outtake ports on the front, so the oil (lubricating the apex seals) was drawn out by the brute force.... I believe that with the side mounted ports of the Renesis comes the huge decrease in oil consumption because it is not sucked out this way any more. Nevertheless this IS an issue and I would surely follow the manual in this point. And always check for the good sap every other refueling.... :o

5w-20 semi-synthetic
 

can I use Valvoline 5w-20 semi-synthetic oil on the 8's. Thanks

The most important pieces of info on the label of the carton are the API Service rating and the ILSAC specification. Ensure that they are API "SL" and ILSAC "GF-3".

Additionally, I've been advising folks to look for BOTH Honda AND Ford specifications for the new 5W20 oils. These credentials indicate the oil meets or exceeds the manufacturers' specs. The Honda spec is good, the Ford spec is best -- it's currently the most rigorous standard for 5W20 oils.

BTW, the "semi-synthetic" or "synthetic blend" label on the oil is, most likely, simply for marketing. I'm not familiar with the Valvoline brews, but it is most likely a blend of highly-refined mineral oil base stock (group II, II+, and III), as opposed to having any "pure" synthetic oil (group IV) base stock in it. Nowadays, the term "synthetic" is more closely associated with performance characteristics, at least for marketing, than differentiating between man-made and dino oils.

Again, as long as the oil is "SL" and "GF-3" you should be OK.

I don't want to revive any dead threads, but the new Castrol Syntec 5w-20 oils clearly label Ford spec right on the front. Does that mean anything when it comes to the Renesis? ...i.e. Can I now use this synthetic oil in my RX-8? Thanks.

What does the Owners' Manual say?

First off, I highly doubt the "syntec" formulation is "synthetic" in traditional terms. It's merely a marketing term. It's more an indicator of performance level or standard for the oil, as opposed to a chemical formulation. It was, in fact, Castrol's court victory against Mobil (mid-1990's?) that paved the way for ANY formula of motor oil to be branded "synthetic" so long as it is highly refined enough and performs well enough. The Syntec is most likely a blend of highly refined mineral oils (probably group II+ and group III), with a proprietary additive package (thus, they can call the oil "synthetic" and charge any price the market is willing to sustain...)

I'm not familiar with all the tech details of the Ford specification for 5W20 oils, but let me reiterate that the most important specs to look for on the label are simply this: API Service SL and ILSAC GF-3. These are MANDATORY specs. Any oil with these specs will be good oils to use.

The Ford spec is based on measurements of how well the oil holds up and protects against wear over a long duration. IIRC, it was in excess of 150K (simulated/tested) miles. Oils with this spec, in addition to the API service SL and ILSAC GF-3 ratings, will be your best bet.

API Service SL and ILSAC GF-3.

Ciao!

Question regarding synthetic oil change
 

My appologies if this has been posted before, I tried a lengthly search and turned up nothing.

When switching to synthetic, has anyone drained the coolers and lines to change all of the oil? This seems like an easy proposition, but I have hit a snag. How do you prime the pump, coolers, and lines? Since nearly half of the oil is sitting in the coolers and lines, I would like to change all of it. Any ideas?

I simply wouldnt recommend goin to synthetic. I was told its so slick and the rotor seals wont set.. ?

Synthetic has been covered many times. The only oil requirement is that it be API certified or ILSAC GF3, and 5w20 grade.
The manual does not prohibit synthetic / say to use synthetic, nor does it say to use regular oil.
If synthetic would be detrimental to the car it would say so in no uncertain terms. Period.
As for flushing out the lines and cooler, I have not heard of anyone doing this.
2-3 oil changes, plus the adding of oil in between and you should be fully converted.
It might be a nice project to undertake though.

I'm currently running durablend synthetic oil in my 8 and I only have 3k miles. I don't think it'll be a problem. And you shouldn't have a need to flush all the oil out of your system. Just change the oil every 3k miles and you should be running full synthetic in no time.

Also remember the stock oil's already semi-synthetic....

synthetic oils will mix perfectly fine with non-synthetic oils

Like they say, don't worry or bother about flushing the left-over oil. Synth and non-synth are perfectly compatible, so after about 3 changes you'll be effectively 100% synthetic.

Regards,
Gordon

Thanks for the help guys.

Synthetic Oil (answer from Mazda)
 

I wrote to Mazda about the use of Synthetic Oil in the Rotary engine, since the manual doesn't say one way or the other... here is what they had to say....

Dear John,

Thank you for contacting Mazda North American Operations. I appreciate
the opportunity to respond to you.

In regard to your inquiry, Mazda recommends using 5W-20 engine oil for
the Mazda RX-8. Please understand, Mazda hasn't done any long-term
testing using synthetic oil with the RENESIS rotary engine. As such,
we don't recommend the use of synthetic oil.

Regards,

Lisa Lasky
Specialist, Customer Assistance E-Business

Ambiguosity.....
 

That, too is relatively ambiguous......

"We haven't done the testing, so we can't recommend...."

Does not say "we recommend you don't use", simply that they have no clue. :o

S

I'm a former 2nd gen and 3rd gen owner. The reason that some people believe that running synthetic is bad for rotaries traces back to the oil injection system used to lubricate the apex seals. Some people think that synthetic oils will not full burn out of the combustion chambers and leave behind a deposit that overtime will eat away at oil and water seals. They think that mineral oils burn better and don't cause this problem since they don't leave behind as much or any deposits. It hasn't been proven that this is true, but there's a lot of people that believe this through prior experience. I think the 3rd gen RX-7 injected something along the lines of one quart of oil every 1,000 miles. Since the RX-8 apparently injects one quart of oil every 10,000 miles, I would imagine that this problem (assuming that it's true) would be far less on the RX-8. In conclusion, I'm uncertain whether synthetic is bad for rotarties, but this is why there is concern about its use.

Actually, you're almost right. A lot of people believe this, yes, but it has nothing to do with prior experience in most cases. A lot of people believe it because a lot of other people said it, or know someone who said it, or was descended from someone who came down from a mountain with "NO SYNTHETIC" written on a stone tablet. When I was trying to decide for myself what to put in my ex (3rd gen) I found only ONE person who actually had a motor blow after using synthetic and found "deposits" on tear-down...and even that taken on its own is hardly damning evidence of anything. I know far more people who said to hell with the rumors and use synthetic in their rotaries, and they've been running strong ever since...they're usually just too smart to bother jumping into the ongoing and never-ending argument. Which reminds me...WTF and I doing, I should know better! :D

jds

Well, the thing is, 5w-20 are semi sythetic blend as is in order to create that weight, I don't think it would make any more difference to use a full sythetic vs a semi (i'm not sure if it's the right word). Eitherway, the lack of testing for full sythetics was most likely due to cost reasons of Mazda up top does not want to spend extra on testing with it.

well no car company has tested it.. to began with no car requres sythentic.. ?

Tell that to VW, BMW, and Mercedes...all companies slapped with class action lawsuits cause they didn't firmly say "synthetics required" for their insane extended OCI's (oil change intervals).

Especially in the 1.8T's, if you run dino for 5k...your gonna get turbo tuds from the dino oil being obliterated by the turbo temps. Enough chunks of sludge in the turbo line, bam there goes the turbo.

I don't believe that is completely the issue. I can't remember where... Europe maybe? Mazda recommends synthetic, and I believe the Mazda shops will use it on a standard oil change. Keep in mind that in Europe, the requirements are different than here in the states for a company to label an oil as "synthetic".

{Opinion}
I believe it is simply a matter of Mazda believing there MIGHT be an issue for some "Synthetic" labeled oils here in the US. I believe they know there are some synthetics here that are safe, they just don't want to promote one or more brands. If you do a search for Synthetic Oil you'll find LOTS of threads and thread entries where people are using synthetic right now with no issues.

Rather than get into the business of "certifying" or recommending some brands against others, Mazda has chosen to be deliberately ambiguous.
{/Opinion}

If you do the due diligence and search all the threads discussing synthetic oil, you'll see that EVERY TIME someone has contacted Mazda North America Operations about clarification re: synthetic oil, their position has NOT been to exclude synthetic oil. Instead they choose to restate your vehicle oil requirements and say they are not RECOMMENDING it. They have NEVER to my knowledge said "DON'T USE IT!!!". Note, that I'm not talking about what some mechanic at your local Mazda dealer told you, because they are kept in the dark about intentions just about as much as us users.

Personally, I'm thinking pretty seriously about switching to synthetic after I have about 5-6 K miles. But I'm not RECOMMENDING it to anyone. :)

Actually I know Evo requires Sythetics.

Once my engine is broken in Im going to change to full syn.

I received this email from Redline Oil today.

I received the following response from Dave at Redline oil.

"Chris,

We recommend and use our products in rotary engines once the engine has been allowed to brake-in. We have used products extensively from the beginning in the rotary engines with very good results. "

Regards, Dave
Red Line Oil

brake-in????
 

why not synthetic?
 

Ok I have read all the posts but can't fine the answer to my question. Why dosn't Mazda recomend synthetic motor oil for the rotary? I was looking at diffrent sythetics online (mobil 1, amsiol, royal purple ect) and some of the sites (Mobil) even said not recomented for Mazda rotary. But why? Dose anyone know a Mazda mole willing to tell us why Mazda says this, whats the harm, they have to know something, I mean for the love of god no other car companys says don't use it, some even ship from the factory with it already in the car.

It is probably because the rotary has oil injected into the combustion chamber, and gets burned off along with the fuel/air mixture. Since one can't generally predict the formulation of synthetic oil, then you can't generally predict how it will burn. While many people have had good luck with synthetics, Mazda probably won't make a general statement about synthetics because of the uncertainty of formulation. Dino oils are more predictable. I am sure that there are many synthetic brands that work fine in the Renesis...

I thougth it might be they were afraid the synthetic wouldn;t fully burn and over time might collect and gunk up the catalictic converted, or even pool in the mufflers, I know sunthetics have a very high burning point.

MNAO told me that since Mazda has not tested synthetic oils in the rotary engine they recommends against it.

Whats got me puzzled is why wouldn't they test with a synthetic, its their flag ship sports car, and has a high preformance engine built and spin up to 9000rpm. Thats senthetic territory.

It's all conjecture...just use cheaper mineral based oil relevant to where you live (in terms of oil weight), check it after every second or third gas fill-up and top up the oil when necessary, change the oil/filter more often than your previous piston engine car (ie. change every 2000 to 3000 miles vs. every 5000 miles), and enjoy the 8 :) It's so easy.....isn't that a song? :)

oh good gracious, not ANOTHER oil thread.....

Stone, I agree with your comments. I've used Mobil ! in every car I"ve had since 1977. I too felt it was ideal for the RX-8 which is why I questioned MNAO about it. It is frustrating!

Royal Purple all the Way
 

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

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. :D

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:

But it's so much fun! :D

Is mobil 1 synthetic ok?
 

Pep boys is having this huge sale where is you buy a calender for one dollar, you can get coupons valid for three free mobil 1 quarts with the purchase of three. With the rants of synthetic running in your car, I want to know if it's safe to run mobil 1 synthetic?

Yes.

If the oil has the API certified for gasoline engines, and the API service SL/energy conserving label on it, then it if ok to use in your car.
This is the only requirement for oil mentioned in the owners manual.
The warranty booklet says you must use fluids specified in the owners manual to maintain warranty.
Synthetic/conventional are not mentioned either way, good or bad.

Yes it is fine, but some people in here do not agree.
I use Mobil 1 0w40 and always have.
Some people also say to mix a little Zaino with regular oil and it will make the inside of the engine shine.
There are a lot of people in here that don't know what a muffler bearing is.

Wether people in here agree or disagree is not rellevent.
What the owners manual says is.
So and so's brother's sister who is dating a guy who fixes rotary engines said that........
Just because someone on the internet says something does not make it right or wrong.
When in doubt follow the owners manual.
If synthetic was a no no it would be spelled out clearly.
I do happen to know what muffler bearings are. I used to think they were to keep the muffler quiet, but as I got smarter I learned that they are used as a spacer if your bolts are too short and you don't own a bolt stretcher.
I would never mix Zaino with motor oil, Mguires nxt wax makes a shinier engine!

What about using mobil 1 0w20? On the carton it says to use 0w20 if you use 5w20 for your car

In theory it should work. 0w20 starts off as a 20 weight oil and then mimicks a 20 weight when hot.
A search of the oildrop forums and hundreds of people will tell you its ok. But again its a lot of "my brothers, sisters neighbor said that....
If you are using a 5w20 dynthetic then a 0w29 synthetic will really make no difference. The lower pour point of the 0w20 and 5w20 are both lower than any cold temp you will encounter.
Some say (brothers sisters aunt) you can use 5w30 in place of 5w20.
Nowhere on the API website does it say to substitute. It says follow your owners manual.
Bottom line" fo;;ow the owners manual. API SL 5w20.