I still haven't found a proper answer to this.. Can synthetic oil be used in a rotary engine? Synthetics are of course much better than regular oils for piston engines but are they better for rotary engine applications?

I do not know about the Renesis, but back when I had my 2nd gen and 3rd gen synthetic was not allowed. Personally, for all my cars, especially the S2000, I have used Mobil 1.

Although I use dino-juice in my 3rd gen, the newest generation of synthetic oil with lower ash content and increased combustibility works great. Remember the rotary has oil injection from a metering pump to lube the apex seals and housings, similar to a 2-stroke engine. The car is designed to burn oil so check it often. There was an issue of carbon build-up and unburnt oil deposits but has since been rectified with new formulation. I change my oil every 1500 miles so the added expense of synthetic isn't really worth it.

As Toadman said, synthetics are fine in a rotary. But what I'm really curious about is which one Mazda will recommend...

Originally posted by m477
As Toadman said, synthetics are fine in a rotary. But what I'm really curious about is which one Mazda will recommend... For my own piece of mind, I'll probably get my oil changes done at the dealership, because after I start working I don't think I'll find time, and besides it's nice to have a list of maintenence history on the car :)

We'll see though... maybe I'll do it myself. It's not a big deal as I do it in my Millenia now... so we'll see what my schedule is like :)

:confused:
What does that have to do with dyno vs. synthetic?

BLAHAHAHAHHAHAHA
anyways, does it really matter? is there synthetics available that are better for a rotary than a given "dino" oil? And im assuming that means natural gass. Ofcourse i would assume so, because synthetics and are designed to do the job of lubrication better than a natural oil but then again i am completely ignorant lol.
________
RECALL PAXIL (http://www.classactionsettlements.org/lawsuit/paxil/)

Originally posted by P00Man
BLAHAHAHAHHAHAHA
anyways, does it really matter? is there synthetics available that are better for a rotary than a given "dino" oil? And im assuming that means natural gass. Ofcourse i would assume so, because synthetics and are designed to do the job of lubrication better than a natural oil but then again i am completely ignorant lol. Dino would refer to DINOsaur :)

yaeh i know, those are known as FOSSILIZED Fuels, or natural oils lol anywho...thanks

What happens if you put GLUE into the oil thing? blahAHAHAHAHAHAHAHAHAHA what about MOLTEN LEAD? are those good for the engine? bblahAHAHAHAHAHAHAHAHAHAH
________
Honey Oil (http://trichomes.org/hashish/honey-oil)

I wonder how long it will be before someone comes out with a special "rotary engine formula" motor oil designed specifically for the needs of the Wankel.

Originally posted by Toadman
...Remember the rotary has oil injection from a metering pump to lube the apex seals and housings, similar to a 2-stroke engine. The car is designed to burn oil so check it often...
What if we put synthetic 2-stroke oil in it?? :confused:

I think we should use oil with a high viscosity to break-in the engine (e.g. 15w40)

Originally posted by BryanH
I wonder how long it will be before someone comes out with a special "rotary engine formula" motor oil designed specifically for the needs of the Wankel.

What are those needs? What viscosity?

Pooman: I think you should try following this adage: " If you don't have anything good(intelligent) to say, don't say it(post it) at all" Please keep your off topic posts about the glue and molten lead in the lounge. :mad:

How much do you think will the Renesis burn? If a lot then using synthetic oil would be cost prohibitive.. Would the Renesis benefit from synthetic oil properties like a very low pour point and high resistance to breakdown and shearing?:

I guess "The manual" will clear it all up :)

I've always read/heard that Synth is not good for a rotary, since rotaries need to burn a little oil, and synth doesn't burn well.

Either way, I personally think synth is a waste of money. Buy Dino, change it and the filter every 3,000, and you'll be fine.

Originally posted by JGard18
Either way, I personally think synth is a waste of money. Buy Dino, change it and the filter every 3,000, and you'll be fine.
WRONG Synthetic oils outperform conventional oil in EVERY category, especially flow at cold/start up temps and hot temps performance. Please do some research here before you post such an ignorant statement.
http://theoildrop.server101.com/ubb/ultimatebb.php

nah, I'll still stick by my statement. I don't believe it's worth the money.

That's not an ignorant statement, it's a statement of opinion.

Try not to be a dick next time.

Guess whats the main ingrediant in syn. oil. I was totally shocked
its the worst thing for internal parts. but its SAND thats right that totally abrasive stuff. Don't ask me how the chemist does it but that totally goes against common sense.:eek:

Originally posted by JGard18
nah, I'll still stick by my statement. I don't believe it's worth the money.

That's not an ignorant statement, it's a statement of opinion.

Try not to be a dick next time.
I'm not trying to be a dick, :) but could you elaborate why you have such an opinion of synthetic oils? I'm talking about group IV and V PAO or ESTER based synthetics like Mobil1, Amsoil, etc. NOT Castrol Syntec.

I'm just speaking from experience. All numbers aside.

I've not had an engine last longer or perform any better by going with synth over dino.

So, at $30 a change, I can't justify it.

Originally posted by Spining Ncnratr
Guess whats the main ingrediant in syn. oil. I was totally shocked
its the worst thing for internal parts. but its SAND thats right that totally abrasive stuff. Don't ask me how the chemist does it but that totally goes against common sense.:eek:


Hey, can anyone explane this sand thing?

:confused:

... It doesn't seem right? Is it synthetic sand? ;)

Originally posted by Quick_lude
How much do you think will the Renesis burn? If a lot then using synthetic oil would be cost prohibitive.. Would the Renesis benefit from synthetic oil properties like a very low pour point and high resistance to breakdown and shearing?:

well, the RENESIS has been said to consume some big amount less (god, my brain is so fried... can't remember the amount) than the 13B, because of a more accurate metering pump (??), or because there are so much more solid perhiphery the apecies (sp :p)... can't remember, some reason, burns less... the 13B really didn't burn much in the first place, like 1 quart every 5000 miles i think... and the RENESIS burns less, it's probably a quart every 7000-10 000 miles or something...

i don't know how much of a benefit the RENESIS would have in a regular street application... i believe, if i have all my sums (in my head) correct, the rotor moves against the eccentric shaft's journal at 2/3's the RPM of the engine, so a good deal slower than a con rod on a crank journal...
even taking the engine up to 9000 rpm regularly, those heat exchangers will take really good care of your oil for you, and synthetic isn't leaps and bounds above high grade mineral oils in terms of slipperiness...
BUT, if you live in a place like Canada, where there are significant tempurature extremes, track the car sometimes, or forget the changes sometimes, synthetic might be a good idea ;)

Need I remind you guys of the forum rules? Comon now calm down :)

Let's just let it wait until we get the manual and Mazda's official word on it, okay? Right now we just speculate and perhaps it can go either way. If Mazda says it's okay to use synthetic then use it, and those that feel more comfortable using dino oils can do so.

Ahh the endless debate!!!!!!:eek:

You guys should read some of the posts on The RX-7 Forum (http://www.rx-7club.com). They are still fighting about this.

Here is my take on this:

The official recomendation by Mazda for the RX-7 is DO NOT USE SYNTHETIC OIL IN THE ENGINE.

Pettit Racing (All well respected rotary shop in FL) says Synth might be OK, but why risk it.

Mazdatrix (Another well respected shop in CA) says the same thing.
This has got to be one of the most frequently asked questions ever!

Here is our answer:
The Rotary engine has an oil injection system that injects small amounts of oil into either the intake tract, carb, or rotor housing (depending on year/model). This is needed to lubricate the various internal seals and surfaces.

The injected oil MUST BURN, and must burn clean. The root answer to the question is that not ALL synthetic oils burn, and not ALLof them burn clean.
The ones that do not burn accumulate until they foul the spark plugs.
The ones that do not burn clean can leave residues of various substances (like ash? plastic? non-organic sand?) that accumulate until the spark plugs foul, or a seal sticks -- could be apex seal, side seal, corner seal, or oil control ring. The normal consequence of a stuck seal is an engine tear down.

In the many years we have been involved in rotary engines, we have NEVER had a problem with GOOD petroleum based oils. They work fine! They are less expensive than synthetics. (We use Castrol 20-50 GTX). They burn clean, etc. etc.

The problem with answering the original question is that it is NOT a simple yes or no. We DO simplify it to a "NO", but that is because we do NOT know whether the specific brand of synthetic the customer has in mind will work. AND, if it does not work, how long will it be before the damage shows up, and how bad will the damage be? Maybe it will take 10,000 miles, maybe 50,000 miles?? Maybe the engine will fail due to something unrelated to the oil, and there won't be enough left to determine why the failure happened.

WE are not willing to take that gamble, are you ?

Then, take a minute to think of WHY you want to use a synthetic. If a rotary engine (properly maintained, oil changes at 3K intervals, etc.) can still be running fine at over 200,000 miles, the engine does not need any more cooling, the gas milage will not be any better, etc. etc. WHY do you want to spend more $$ and gamble on engine and/or spark plug damage? (If you are into the fossil fuel thing, pollution, depleting our resources, etc. then you should not be driving ANY car!)

We are not chemists, and we do not have the time, $$'s, nor inclination to do 100K mile tests of various synthetics in rotary engines.

We DO use synthetics in the transmissions and rear ends - it works fine.

Anyway - that is the MAZDATRIX version of the synthetic question.


Racing Beat (Another shop in CA) Loves Royal Purple Synth.
Racing Beat has been recommending the use of synthetic oils in rotary applications for several years. Our research has found that synthetic oils provide superior friction reducing between sliding surfaces, reduced foaming, and lower oil temperatures. We have tested several different synthetic oils and have found that while most offered improved wear and lower oil temperatures, none offered any horsepower gains... except for Royal Purple!

Our in-house testing has yielded up to a 2% performance increase after changing from mineral-based oil to Royal Purple Synthetic Motor Oil. How could this be? Jim Mederer, co-founder and chief engineer at Racing Beat, was truly puzzled. With over 35 years of professional racing experience under his belt, he has seen and tried just about every “new” lubricant that hits the market. All offered better wear and lower oil temperatures but none offered any horsepower improvement. After spending time consulting with the engineers at Royal Purple to better understand the reason for the horsepower gain, it was explained that the secret was the proprietary ingredient “Synerlec”. This Synerlec ingredient provides an ultra-slick film on internal engine components to significantly reduce power-robbing friction. Less friction equals more power!

Other professional engine builders have confirmed that Royal Purple Synthetic Racing Oil delivers measurable horsepower gains. Independent dyno tests show increases up to 5% (on smaller displacement engines) with nothing more than an oil change.

Give Royal Purple a try with your next oil change!

There are lots of people on the RX-7 board that swear by synth (A lot of them use Moble 1), but others say it's a bad Idea in the long run.

I have heard people say that Synth is OK as long as you don't use it during break in & as long as you haven't been using Dino for too many miles (like 40K) because of a chemical reaction with old Dino soaked rings & seals.

I tend to agree with thoughs that error on the side of caution. Why risk it. If you are hell bent on using Synthetic I would only use one that is marketed for Rotarys like Royal Purple. I think that Racing Beat is reputable enough to trust.

PS in a piston engine Synthetic Oil is Great! but............................................ If it ain't a rotor, it ain't a motor!

Yes Boss.. :p Personally I'm not very familiar with how the rotary engine "uses the oil" and "treats" it. So once again, woud the synths cold temp flow and high temp resistance properties benefit the rotary the same way it benefits a piston engine?

Ooops, posted at the same time.
20W50?! Wow, that is a HEAVY oil.. much too heavy for Canada.

Short answer: Yes (if you are willing to risk it.)

The whole issue is because the rotary engine injects a small anount of oil into the combustion camber for lubrication of the seals, there is concern about what happens after the oil goes through the combustion cycle, what residue is left behind and what happens to it.

This is not an issue with Dino Juice - it burns off clean.
This CAN BE (hence the controversy) an issue with Synth.

Originally posted by Quick_lude
20W50?! Wow, that is a HEAVY oil.. much too heavy for Canada.

well, i think these guys are running FD's, and they don't have to worry about COOOOOOOLD (!!!) start-ups like you do, and we all know about the heat thing once those 13BREW's get their legs all stretched out... just a precaution in an engine which runs more than hot enough for it.

Originally posted by Styjan
The whole issue is because the rotary engine injects a small anount of oil into the combustion camber for lubrication of the seals, there is concern about what happens after the oil goes through the combustion cycle, what residue is left behind and what happens to it. This is part of what I was getting at in referring to a special 'rotary formulated' oil. Something that offers the extreme temperature protection of synthetic, but is also designed to burn clean in the combustion chambers.

I'm far from an expert on this but I imagine the rotary also uses slightly different metals that might require slightly different lubrication properties.

Maybe we should E-mail some Oil producers like Castrol, Exxon, Mobil,... in name of the RX-8 and/or RX-7 Forum and ask their solution of this neverending "Rotary Engine Oil Quest"??

Originally posted by wakeech
...the 13B really didn't burn much in the first place, like 1 quart every 5000 miles i think... and the RENESIS burns less, it's probably a quart every 7000-10 000 miles or something... I guess you've never owned a rotarty, eh? The owner's manual (I'm not even talkin' about the shop manual) of my '86 NA sed that depending on conditions, burning as much as 1 qt. in 500 miles is within spec limits. My personal experience was something like 1 qt. in 1k-3k, approximately.

---jps

Originally posted by Sputnik
I guess you've never owned a rotarty, eh? The owner's manual (I'm not even talkin' about the shop manual) of my '86 NA sed that depending on conditions, burning as much as 1 qt. in 500 miles is within spec limits. My personal experience was something like 1 qt. in 1k-3k, approximately.

---jps I don't think many people have owned a "rotarty".. Maybe a rotary :D

Originally posted by Hercules
I don't think many people have owned a "rotarty".. Maybe a rotary :D Hey Hey Hey... Do you want me to spend all sorts of time spell-checking and re-spell-checking my notes here, or would you rather I'd rip through this response and go spend my time pulling pictures from Boowana instead?

I didn't think so... :p

---jps

Of all the words you spelled wrong though....

*shame shame* :D

Here's your special "rotary formulated" oil - at a mere $107 per 4 liter can.

Originally posted by Sputnik
I guess you've never owned a rotarty, eh? The owner's manual (I'm not even talkin' about the shop manual) of my '86 NA sed that depending on conditions, burning as much as 1 qt. in 500 miles is within spec

nope. hope to call a black FC my own someday (i thought i kept repeating that too often, myself ;)).

anyhoo, yeah, i did remember the number wrong... i musta just added a zero on there in my head... :confused: whatev, it's all kinds 'o' good now. thanks. :)

as for jdachik's rebottled "Mazdaspeed" brand oil, i wonder what it really was...???

As the proud owner a 94 FD RX-7, I have used nothing but synthetics since the engine broke in. I remember the skepticism I possessed when I first tried the mobil 1 15-50, but it was all vanquished after starting the engine. The car idled smoother, and the engine seemed to just run smother all around. With the RPM the turbos reach in the car, I would worry about shear and brakdown in the oil, so synth is safer, and the ash contents have come down to negligable levels in some brands.

Another thing that made me decide to go with synth was that I NEVER saw any posts on the forum about anyone having actual damage occur because of synth oils. after running synth for 20,000 miles on my FD, the engine still purs like new.

Really the ONLY concern of using synthetic oils is the ash content. if you want the benifits of synth oil, but don't want the ash risks, disconnect the OMP and put a premix in the gas. or there is some comapny that sells an OMP adapter to have it inject 2-stroke oil for a seperate resivior instead of going from the oil pan.

If you research the issue with Rotaries and Synth, it was the Ash content from the engine burning the oil. Actually when originally tested there was only one Synth that caused an issue but since Mazda (small and poor at the time) didn't want to have to deal with a potential lawsuit they just made a blanket statement to not use Synth oils. And as for Synth being better lubricating, I have personally tested several oils, and additives with a bearing tester and surprisingly Castrol GTX was the best lube of all of them. Of course that was just a short 5 minute/per oil test, but it was enough to convince me. If you want I can get the number about PSI of pressure to the bearing for different oils, I for sure have the Castrol.

It is ok to run Synths in a rotary, but you MUST change the oil at the same intervals as dyno. Must! Must! Must! Do not think you can go longer between changes just because you are running synth. Change it at 3000 or before. Can I stress that any more?!

With that said, I run a Dyno oil, Castrol 20w50 in my FD and TurboII REPU, as the only synth I would run is Royal Purple, and at $5 a quart, I cannot justify the cost, when I can get the dyno juice for $0.99/qt at Walmart.

Originally posted by rotarynews.com
It is ok to run Synths in a rotary, but you MUST change the oil at the same intervals as dyno. Must! Must! Must! Do not think you can go longer between changes just because you are running synth. Change it at 3000 or before. Can I stress that any more?!

With that said, I run a Dyno oil, Castrol 20w50 in my FD and TurboII REPU, as the only synth I would run is Royal Purple, and at $5 a quart, I cannot justify the cost, when I can get the dyno juice for $0.99/qt at Walmart. You bring up a good point Dan, because rotaries burn oil :)

Can't forget that now! :cool:

An additional point, maybe not as obvoius, but gas does get into the oil... with turbo rotarys in particular. If your oil gets soaked with gas, the combustion chamber will not seal, your compression will go way down, and your rotary will not start. Just as flooding wipes away the oil coating, gas in the oil does the same.

it has yet to be determined if the RENESIS is as prone to flooding as the 13b N/A six port, but if you ever do flood your RX-8, change the oil right away.... no exceptions!

Wouldn't burning off oil cause some emissions problems for the RX-8? Would be pretty hard to meet the new lower emission standards if you're losing a quart of oil every 1000 miles.

Maybe Mazda has improved their design since the last rotary. If not, this engine sounds like it'll run like a 2-stroke. Since most companies that used 2-strokes in their products (Jet-skis mostly) are now moving to 4-strokes for better emissions, going the other way would definetly not be good.:eek:

:) welcome my friend. it sounds like you sorely need to bone-up on your rotary tech... PLEASE!! RELISH THIS TIME!! :D it is fantastic... ahhh, to feel that awe again... i'm sure i'll have a fat nostalgic shock when i buy my first wankel

it is in fact very simliar to a 2 stroke engine, and yes, burning oil does pose a small concern with emissions, but the combustion cycle in the rotary is far, far more efficient than a 2-stroke piston engine, with a very long burn cycle... this, along with emissions catalysts makes this engine a very low emitter...

NOx was always good, and with side port exhausts, unburned HC emissions are coming well down too...

Per my research with a few Rotary developers in the US (Roger M., Jim D. & Rick E.). The rotary CAN use Synthetic oils in race trim. But, due to emission problems you cannot use it in productions vehicules... due to catalitic converters. Period.

The enigne will burn more oil if you drive it harder. The oil metering pump that injects oil into the combustion chambers pumps at different rates depending on how you drive the car. At full throttle all the time, you'll burn a lot.

Tons of people have been using synthetic oils in rotaries without any problems for some time. You can do oil analysis to get an idea of what intervals you should be using or what oil works best for your engine and operating conditions. Or you can just go along with what the manual or other owners recommend, which is also a reasonable choice, in my opinion.

Frequent oil changes are recommended for rotaries. I wonder if extended intervals could be used with synthetic in the RX-8. Oil analysis could help make that determination. On the turbo cars, the oil is pretty beat after 3000 miles, so I don't even g that long. Fuel dilution is a big factor.

I like synthetics. I use Royal Purple in my RX-7. The previous owner of my car used synthetic blends for a long time (based on the dealer history of service that I looked up) and it didn't seem to damage my cats.

I think the RX-8 rotors might have an extra oil control ring, which might reduce oil consumption or fuel dilution.

You need oil to lube the apex seals in the combustion chamber, so working to eliminate consumption is not a reasonable goal for an owner, in my opinion. Some folks with FDs have actually had the oil level go up or at least not drop. The verdict on that phenomenon was that they had lots of fuel dilution rather than no oil injection. If anything, you might want to pre-mix or electronically increase the amount of oil consumption to reduce combustion chamber wear. I think Mazda has to stike a balance between emissions and engine longevity when they design the system. As an owner, you might choose more longevity at the expense of more emissions if you decided to change that balance. However, I don't really feel compelled to change it.

-Max

BrianH- They already make many custom Rotary Oils that are sythetic now. I think RE Amenia(Bad spelling I know), Mazdaspeed (japan), Many rotary tuners make thier own oils. Royal Purple is my personal favorite.

Kyle Lancaster--Double Agent Salesman

Racing Beat recommends Royal Purple synthetic motor oil. They claim a modest INCREASE in horsepower.

Originally posted by Donny Boy
Racing Beat recommends Royal Purple synthetic motor oil. They claim a modest INCREASE in horsepower.

...i think that's 'cause Racing Beat is a RP distributor/vendor, and would be in their best intrest to say so regardless of whether it's true or not for everyone.

of course, RP is a great oil, but i'm uncertain if it would be well suited to RENESIS use yet.

Correct oil to use is a mineral oil from Mazda 5W-30 designed for the rotary.

Ask your Mazda Delaer they should have it.

If not we do here.

Run it in my 7

Best stuff by far !

HoW much does it cost? just wondering...

it would be around $20 us

for 4 litres

Originally posted by Maestro
Correct oil to use is a mineral oil from Mazda 5W-30 designed for the rotary.

Ask your Mazda Delaer they should have it.

Run it in my 7


Do you know what qualities in this oil make it "best for rotaries"?

Maybe this is a dumb question, but can anyone explain why the Rotary needs to consume oil? In a piston engine, the ring is lubricated with oil, yes? The ring is inside the cylinder, yes? And therefore when the gas combusts in the cylinder, isn't some oil going to be burnt there too? I'm not very knowledgeable when it comes to engines, but I don't understand why the Rotary must burn so much more than a piston engine.

Originally posted by DreamWarrior
The ring is inside the cylinder, yes? And therefore when the gas combusts in the cylinder, isn't some oil going to be burnt there too?

in pistons engines, the combustion chamber at the head of the piston is separated from the bottom part of the piston/crank/connecting rod by piston seals. these seals are rings that fit into a groove near the head of the piston and fill up the space between the piston and the cylinder wall, combustion on one side, lubrication on the other. piston engines tend to burn oil too when those rings crack/break/wear down etc.

in a rotary, the apex seals (at the 3 corners of the rotor) need to be lubricated. however, combustion occurs on both sides of the seal so you have to inject oil into the chamber with the air and fuel to lubricate the seals, thus it burns more oil.

Originally posted by lefuton
in a rotary, the apex seals (at the 3 corners of the rotor) need to be lubricated. however, combustion occurs on both sides of the seal so you have to inject oil into the chamber with the air and fuel to lubricate the seals, thus it burns more oil...

...but now that the exhaust ports are located on the side housings, the apex seals needn't have so mcuh oil for lubrication... what, something like less than half the last 13B?? it's getting less and less all the time: it's not something to worry about from a cost stand point, or a "am i going to run out of oil?" issue, it's really just something to battle with as an engineer in charge of getting the RENESIS past emissions tests.

A quick thought.

Would a double apex seal be possible?

Widen the seal slightly and cut a runner along the top edge then inject the oil into the runner.

OK, the leading edge wont get direct lubrication but it should be enough and perhaps it would further reduce oil consumption and emissions.

hmmmm... there are 2 and 3 peiced apex seals, but those are all cut so that the seal spreads in two or three directions (to each side and up)... it's obviously a good design for the reason you pointed out, but there's gotta be a reason they can't do that....
maybe the oil between the seals would cook and stick, causing the seal to score the block??? i dunno, just throwing out ideas... i need to sleep ;)

The rotary uses oil injection to get some lubrication into the combustion chamber for the apex seals and probably also for various other areas outside of the path of the side seals. It would be hard to do that via other means.

Double apex seals probably wouldn't work because they would be too fragile if they were small enough to both stay in contact with the rotor housing at all times. And besides, it would still burn some oil that way and the current injection systems work fine, so what's the point. You might even be able to use some apex seals with little oil passages in them, but that would also weaken them, and again Mazda already has a system that works fine.

I think the RENESIS needs less oil injected because the absence of peripheral ports keeps the injected oil in the chamber, rather than flinging it out the exhaust port at the end of each combustion cycle.

Just check the oil when you get gas. It is okay if you are dressed up and miss this step for a fill-up or two here and there. You probably won't need to check as often with the RENESIS since it burns less oil. It isn't that hard to keep it topped off if you are used to doing it. Previous RX-7s have had idiot lights for low oil level if you forget, but they only come on if you are a quart or so below the minimum fill mark, so you shouldn't run into that normally. I think it even buzzes at you so you can't ignore it.

-Max

Has anyone asked this question to one of the Mazda techs at any of the tech briefings or Mazda Rev It Up events? Just curious.

There you go...fuel dillution in the FD seems to be pretty bad. I get a distinct fuel smell in my oil at pretty moderate intervals. I have no idea if the Renesis will be any different, but according to some of the things I've read, synthetics (in particular Royal Purple, which happens to be what I use) tend to not compromise their lubricating abilities in the presence of gas. This, and the fact that I have turbos, and finally the fact others have alluded to in that everyone has a friend whose engine died after synthetics but nobody in the first person seems to have that problem...well, all those are why I went synthetic.

jds

Originally posted by rotarynews.com
An additional point, maybe not as obvoius, but gas does get into the oil... with turbo rotarys in particular. If your oil gets soaked with gas, the combustion chamber will not seal, your compression will go way down, and your rotary will not start. Just as flooding wipes away the oil coating, gas in the oil does the same.

it has yet to be determined if the RENESIS is as prone to flooding as the 13b N/A six port, but if you ever do flood your RX-8, change the oil right away.... no exceptions!

Racing Beat is a distributor for a number of synthetic oils, and in fact has been for years, but never made that claim about any of the others.

jds

Originally posted by wakeech


...i think that's 'cause Racing Beat is a RP distributor/vendor, and would be in their best intrest to say so regardless of whether it's true or not for everyone.

of course, RP is a great oil, but i'm uncertain if it would be well suited to RENESIS use yet.

I still don't use synthetic motor oil because I still fear buying a brand that doesn't burn off well. Until I see some lab proof through extensive testing which brands burn clean and which do not, I'll stick with dino juice.

However, I do use synthetic 2-stroke oil in my fuel as its very nature is to be consumed in the combustion process. Since the oil is mixed in with the fuel, you guarantee lubrication to almost every nook and cranny within the combustion chamber.

Can you show lab results indicating that synthetic motor oils do NOT burn well? Frankly, this high ash content, not meant to burn stuff is more myth than reality IMO. A while back, a Royal Purple rep who happened to be an RX-7 owner and participant on the "big list" posted a detailed lab report on ash content and numerous other things and the synthetic was no worse than the benchmark non-synthetic oil. I seriously doubt Mobile 1, or Redline, etc are any worse in this regard either, although I'll be perfectly willing to eat my words when somebody shows up with lab results saying otherwise.

jds

Originally posted by evel333
I still don't use synthetic motor oil because I still fear buying a brand that doesn't burn off well. Until I see some lab proof through extensive testing which brands burn clean and which do not, I'll stick with dino juice.

However, I do use synthetic 2-stroke oil in my fuel as its very nature is to be consumed in the combustion process. Since the oil is mixed in with the fuel, you guarantee lubrication to almost every nook and cranny within the combustion chamber.

I absolutely agree with Mr.evel33, a fine synthetic 2-stroke oil, with its 'super-lubricity' will be joining my premium at the pumps.
Mixed about 200:1 ratio, it can do no harm. Two stroke engines actually develop more power as a side benefit, due to the oil film sealing the chambers more efficiently.
Red Line makes a full synthetic that burns absolutely clean at 50:1, and has the best lubricity in the business - they sell it as 'Kart' oil, Racing oil and 'Superclean Two-stroke'.
S

Originally posted by bureau13
Can you show lab results indicating that synthetic motor oils do NOT burn well?

No I can not, and it's that very uncertainty that I choose not to experiment with my engine and cats until I am sure. There is a reason why, during the RX-7's run, that Mazda recommended dino juice. Perhaps that recommendation may be different this time around with the RX-8, but until owners in the US can confirm, or perhaps members like East Moon and JSG, it's only speculation what Mazda will say.

This is not to say that I'm arguing against the use of synthetic or anything remotely like it, nor am I trying to convert anyone to dino. All I'm saying is that I personally choose not to use it. That's all. If you've been using synthetics thus far for your rotary and have had no ill effects, then great, I am happy for you. You can continue doing what you've been doing, and I'll continue what I'm doing.

(ugh! that's the problem with this tired old topic)

My only issue wrt synthetic in the Renesis is...is there any tangible benefit, given that you're probably going to change it often anyway? For the FD, I think the answer is a resounding YES, due to the turbos. However, with a NA motor...I don't know.

jds

Originally posted by evel333
This is not to say that I'm arguing against the use of synthetic or anything remotely like it, nor am I trying to convert anyone to dino. All I'm saying is that I personally choose not to use it. That's all. If you've been using synthetics thus far for your rotary and have had no ill effects, then great, I am happy for you. You can continue doing what you've been doing, and I'll continue what I'm doing.

(ugh! that's the problem with this tired old topic)

Originally posted by bureau13
My only issue wrt synthetic in the Renesis is...is there any tangible benefit, given that you're probably going to change it often anyway? For the FD, I think the answer is a resounding YES, due to the turbos. However, with a NA motor...I don't know.

Resounding yes? What are you talking about? This has nothing to do with turbos.

The problem has always been unique to the rotary in that If a particular brand of synthetic oil does not burn off in the combustion cycle, it, or what ever is left of it, will be flung out of the peripheral exhaust port and will eventually clog the pre-cat or main cat, causing a back up in exhaust flow, increasing heat in the area of turbos and exhaust manifold.

Again, you're citing "data" that at best is unconfirmed. I have seen no REAL data that indicates that synthetic does not burn in the combustion cycle, and some that suggests that it does. Second...we're getting a little off topic here I think...regarding the FD, which has turbos, the question of whether to use synthetic is very much relevant to the turbos. They are the items receiving the bulk of the benefit, so if you're looking at it from a cost/benefit perspective, they ARE most of the benefit. Hence my comment about not knowing if synthetic makes sense for the RX-8, even putting aside the age-old discussion of it with rotaries in particular.

jds

Originally posted by evel333

Resounding yes? What are you talking about? This has nothing to do with turbos.

The problem has always been unique to the rotary in that If a particular brand of synthetic oil does not burn off in the combustion cycle, it, or what ever is left of it, will be flung out of the peripheral exhaust port and will eventually clog the pre-cat or main cat, causing a back up in exhaust flow, increasing heat in the area of turbos and exhaust manifold.

Originally posted by bureau13
Again, you're citing "data" that at best is unconfirmed.

No citing at all, and certainly no more "confirmed" than your previous comments in defense of the use of synthetics. You are obviously quite set in your decision--good for you--no need to defend them from the likes of me. And please don't think I'm trying to convince you that synthetics are bad, or persuade you to switch to dino, because I respectfully am not. All I was saying is that I choose not to use the stuff. My reasons are my reasons and I won't be swayed any less than you will without any proof.

Originally posted by evel333
no more "confirmed" than your previous comments in defense of the use of synthetics

...other than by owners, not to mention Mazda, whose had trouble with running synthetic oil... i know that there are those who have no problems (Racing Beat lays claim to this, but they're a Royal Purple distributor) and i know that there are those who say they have had a problem with fouled cats, plugs, etc...

But you see, this is the problem. Who are these people with clear synthetic-related problems? Where are they? Go post on the RX-7 forum or on the mailing list and try and find anyone with real problems...you will find at most a few who will make comments like "I started using synthetic and then I had to rebuild my motor, so synthetic must be bad." Of course, most FD owners who use dino-juice have to rebuild their motors also. As for fouled cats and plugs....find an RX-7 owner who hasn't had any problems with fouled cats and plugs? Its not exactly uncommon to have these problems, and by far most owners do not run synthetic oils.

jds

Originally posted by wakeech


...other than by owners, not to mention Mazda, whose had trouble with running synthetic oil... i know that there are those who have no problems (Racing Beat lays claim to this, but they're a Royal Purple distributor) and i know that there are those who say they have had a problem with fouled cats, plugs, etc...

Well, if all you were saying was that you choose not to use it I would never have posted a response. I myself mentioned in this thread that I didn't know if it would be worthwhile to use on an RX-8 even if the bad for rotaries stories are false, so I certainly don't care if you or anyone else uses it or not. Earlier in the thread you stated as fact that synthetics don't burn well. THAT is why I responded, and that is what I am arguing against. Use it, don't use it, I really could not care less...I just wish people would stop using tired myths with no supporting data to justify their decisions.

jds

Originally posted by evel333

No citing at all, and certainly no more "confirmed" than your previous comments in defense of the use of synthetics. You are obviously quite set in your decision--good for you--no need to defend them from the likes of me. And please don't think I'm trying to convince you that synthetics are bad, or persuade you to switch to dino, because I respectfully am not. All I was saying is that I choose not to use the stuff. My reasons are my reasons and I won't be swayed any less than you will without any proof.

Mazda spent millions to make this 5W-30 Mineral oil.

So use it !

If was mean't have synthetic oil it would come with it.

So....Mazda has deliverd the RX-8 to some customers in Japan, right? And they came with owner's manuals, right? Which means we should have an answer straight from Mazda on what they recommend for the RX-8.

So, someone who has got one, pipe up! What's the answer? What oil is recommended?

Anyone?

Hello?

ECHO...Echo...echo...

I work for Mazda all rotary engines come with Mazda 5W-30 Mineral oil.

If you want more you can buy MazdaSpeed 0W-30 Mineral but its really expensive.

I can send you some info in pdf format if you would like on the 5W-30

Is it the standard SJ oil that you can find anywhere? Or is it something special? I'm assuming it's just normal 5W-30.

Its the standard Mazda 5W-30.

But it does have rotary additives and is the best oil to use on RE's !

Apart from the mazdaSpeed stuff which is for Rotaries only !

Please tell me, what exactly is a "rotary additive."

jds

Originally posted by Maestro
Its the standard Mazda 5W-30.

But it does have rotary additives and is the best oil to use on RE's !

Apart from the mazdaSpeed stuff which is for Rotaries only !

?????? i DIDN'T MAKE IT

Maybe it has those little cartoon rotors with the hand and legs and smiley faces like on the mazdaspeed T-Shirt.

LOL

What additives does piston stuff have ????

I don't think oil companies give away there special additives ?

Damn, I had this vision of you stooped over a big cauldron of boiling oil. :-D

Seriously though...special rotary additives? I'm highly skeptical of this. I've seen enough marketing speak to know it when I see it!

jds

Originally posted by Maestro
?????? i DIDN'T MAKE IT

Maybe it has those little cartoon rotors with the hand and legs and smiley faces like on the mazdaspeed T-Shirt.

LOL

What additives does piston stuff have ????

I don't think oil companies give away there special additives ?

there might be less anti-foamants or additives which enhance its combustability... speculation, but these are the sorts of magical things a chemist can do; it seems extremely plausible that an oil can be developed for a wankel engine which wouldn't work nearly as well in a piston engine.

Maybe. When did this stuff first appear? I could be wrong, but I don't remember any of my previous RX-7s (I've had 3) manuals making any reference to special oil, other than the well-known "don't use synthetics" mantra. If its actually more combustable, it should be a testable, measurable trait, and you would think Mazda would be trumpeting that data. If they spent these alleged millions developing it, you would think they would want people to buy it. I don't know, I haven't really seen that happening. Of course, I've avoided Mazda dealers like the plague since all the rotary mechanics bolted when the FD went away! Personally, being the skeptical and cynical person that I am, I believe the "marketing breakthrough" explanation. I could be wrong of course. I just wouldn't bet much money on it :-)

jds

Originally posted by wakeech
there might be less anti-foamants or additives which enhance its combustability... speculation, but these are the sorts of magical things a chemist can do; it seems extremely plausible that an oil can be developed for a wankel engine which wouldn't work nearly as well in a piston engine.

Originally posted by bureau13
being the skeptical and cynical person that I am, I believe the "marketing breakthrough" explanation.
jds



i'm a skeptic too: i was only saying it's possible that this oil was developed as such.

...uh, when??? i've seen (very expensive) cans of it with the 787B colours all over them, so quite a while i imagine.

I'll talk to the technicians here if not I'll talk to my man at R & D @ Mazda Japan !!

10 gets you 1 that this "Mazda 5w30 special rotary oil" is just a rebadged Castrol, Quaker State or whatever else.. Unless someone proves with a chemical data sheet that there is an additive that benefits rotary engines..

Btw, would the superior cold flow properties of synthetic oils be advantageous in a rotary engine? They are very much in a regular piston engine..

newbie here... been reading for awhile though. I actually worked (co-op) for almost a year in the ExxonMobil Research labs where they develop all these oils.


I'll first say I have never personally seen a rotary on a testing stand, but I have a lot of knowledge about the synthetic oils. First, they do offer superior performance with respect to friction and temp extremes, and pretty much every other aspect. That is a fact.

I'm just reading along here and there are a few things I don't really get...

In a piston engine, oil does get burned in combustion (as much as a quart in 2000 miles in some engines even without problems) as the oil film on the side of the cylinders gets burned off. This has never caused a problem with piston engines. In fact, sythetics burn cleaner then conventional oils due to the fact synthetics are much more refined. All my time working at XOM I have never heard of ash problems in SYNTHETIC oils, rather the other way around. In order for a synthetic to be a true synthetic, it has a PAO chemical structure which allows for no impurities to exist. All the oils formulated MUST be compatible with catalytic converters when they burn off in order to be certified - this is the reason AMSOIL oils are not certified but I won't get into that here. Currently there is a ton of focus in the diesel market for synthetic oils because they will be needed in order for engines to pass the upcomming very strict Euro emissions laws. Now it is true the synthetics resist burnoff better then dino oils. However, this usually refers to the oil boiling off and not being injected into the combustion process.

Also, regular piston engines experience gas dilution. Gas dilution is actually one of the biggest problems even in piston engines. Again though, synthetics offer better protection against gas dilution as the gas is a bit less soluable in the synthetic oils.



If you have any questions, Mobil has a tech service e-mail and phone number... just check the website, its listed somewhere. I know in fact the line is manned by people who know what they are talking about and if they don't know the answer they find someone that does!

Its not a piston engine though :P



Originally posted by Quick_lude
They are very much in a regular piston engine..

welcome pr0ber!! :D

glad to see someone with first hand knowledge here...

anyways, i'd love to hear more about the whole AMSOIL issue, 'cause i'm not a big oil officianado...

one thing that doesn't make sense though: you say synthetics burn "cleaner", but resist burning better??
just to clarify the problem with oil combustion in rotaries, is that the apex seals coke up quite badly if the oil isn't burning well... you say that it does fine in the cats, which is good, but the whole of the inside of the engine is swept: almost no surface inside a wankel isn't sealed off from another area in the combustion chamber(s)... this, and the strange shapes of all the volumes in the engine, creates a lot of cool zones, which i suppose would create an environment which has a greater capacity to varnish or coke up oil in the wrong places (anywhere)...
the only problem that might arise from "dirty" or "impure" oils would be on the pollution side, unless there are things suspended in "less refined" mineral oils which would not only pollute but create bad-black-crud...
???

This is from the Mobile 1 website <A href="http://www.mobil1.com/products/faq.jsp?catId=18"><U>FAQ</A></U>

Will the use of Mobil 1 with SuperSyn™ void my new-car warranty?

With the exception of the Mazda rotary engine (Mazda does not recommend anysynthetic motor oils for its rotary-engine vehicles), the use of Mobil 1 with SuperSyn™ will not void new-car warranties. Mobil 1 with SuperSyn™ exceeds the API and ILSAC engine oil service requirements of all new-car manufacturers, both import and domestic. If in doubt, always check your vehicle owner's manual or contact your vehicle's manufacturer.

Originally posted by Maestro
Its not a piston engine though :P
It would help if you quote the whole paragraph like this:

"Btw, would the superior cold flow properties of synthetic oils be advantageous in a rotary engine? They are very much in a regular piston engine"

Instead of quoting just one sentence out of context. :confused:

Let me translate.. the cold flow properties of synthetic oil are great for piston engines. Would these properties be as desired in a rotary engine. Better?

Well this is what I got told.

One type of fully Synthetic oil swells up a oil seal in the engine (Can't remeber which one?) The oil ????

Can't remember that either ?

But this is the reason behind Mazda saying not to use synthetics. I've run Semi's with only the following results:

I ran Castrol Protec Semi Syn in my FC RX-7 LM. Had no problem but it did go through it quite qucikly.

I then moved to Penz Semi on the FD which was okay good oil pressure but still had consomtion probs.

Now I use the Mazda 5W-30 in the FD. And its the best oil by far.

I get really good oil pressure and it actually doesn't have consumption issues !!!!

Thats my 0.02c :D

Hope it helps :)

But this doesn't make any sense still.. I thought the rotary engine HAD to consume oil as per design...?? Unless you mean excessive consumption? :confused:

Originally posted by Maestro
Penz Semi on the FD which was okay good oil pressure but still had consomtion probs.

Now I use the Mazda 5W-30 in the FD. And its the best oil by far.

I get really good oil pressure and it actually doesn't have consumption issues !!!!


i thought once you started to use synthetic lubricants that you couldn't go back to mineral oils, as the "conditioning" effect (the oil does in fact saturate the seals, which contributes to help stop leaks) of the synthetic would be lost and you'd end up with leaky seals... this isn't a problem with semi-synthetic oil??

You can go back to mineral oil after synthetics. The biggest issue would be switching to a synthetic oil on a high km engine that has only seen dino juice throughout its life. Since there is crud built up from the dino juice on the seals, the synth will slowly clean that off and the seals could start leaking.

Originally posted by Quick_lude
Since there is crud built up from the dino juice on the seals, the synth will slowly clean that off and the seals could start leaking.

ah, ok. :) spiffy.

what's the diff between mineral oil and dino juice?

and i thought Mobil 1 is semi syn now?

Originally posted by TerenceT
what's the diff between mineral oil and dino juice?

and i thought Mobil 1 is semi syn now?
Commonly mineral oil and dino juice referr to the same thing, ie Group II or III based oil. Group II is the "regular" stuff, Group III is severly hydrocracked "semi-synth".
Group IV is the good stuff based on PAO or ESTER basestocks which Mobil1, Amsoil, Redline, etc..