We buy the Idemitsu bottle for 15 USD which is 13 euros. It is also expensive for us too.

 

So I just had my engine replaced under warranty at 99k. You can mosey on over to the new engine club thread if you're interested in hearing how it died.

At any rate, I got to hear the dealer/Mazda perspective on "no synthetic oil" and it got me thinking. Coupled with their demands for oil change records, I suspect the main reason they don't want people using synthetics is because of the oil drain interval. They want people topping off the oil and making sure it's changed, and not thinking everything will be hunky-dory because they used synthetic oil rated to 20,000 miles and they don't ever have to change or fill it.

I don't know. Maybe that's too simplistic or I don't understand the issue. The talk about how synthetic "coats" the engine and doesn't burn. But my car had poorer compression after they ran engine solvent through the motor and let it sit for a night, so it seems like there's more of a wear problem than a carbon problem out there these days.

 

Wear is a problem. (Apex, due to lack of lube)

Design is another. (not enough lube spot, at least for S1)

 

A few years ago at Sevenstock I met the head of Mazda's rotary engine department. He also helped formulate Idemitsu btw. He told me exactly what the story is with synthetics and why Mazda says not to use it in rotaries. It has nothing to do with the fact that synthetics in general are bad and conventionals are good but rather with the fact that they found an issue that concerned them with A certain synthetic oil that just so happens to be the most widely used synthetic in the world. The issue actually has nothing to do with the fact that the oil uses a synthetic base stock but rather with something in the formulation of that oil. They can't just name that company and say not to use their synthetic as this leaves the door open for lawsuits so they make it an all or nothing statement. You either can or you can't. They found one they didn't like therefore you can't. It's as simple as that. The fact that this particular oil was a synthetic was a coincedence and only found because they were testing synthetics. There very well may be conventionals that have the same issue but since they weren't testing conventionals, they don't know about them. Now that's a scary revelation!

I stated this back then and even zoom44 was standing next to me during the discussion. I even relayed this info here and yet people still kept speculating as to what the issue was. This is it. I got it straight from the mouth of the highest rotary engine person in the world. There is no one with an opinion who knows better than he does. Some people just don't want to know.

As I said, synthetic oil has absolutely nothing to do with anything. Mazda uses it themselves in their own race engines and it also has nothing to do with any special mythical "rotary safe" formuated synthetics that many people claim exists. Most oils (synthetic or otherwise) are "rotary safe". The problem in the S1 RX-8 engines is oil metering and nothing else. The center of the apex seals don't get enough lubrication. Mazda tried raising oil metering rates to compensate but all this did was to add more oil which didn't burn off as well and left more carbon deposits while the center of the seals still received less than optimum lubrication. The solution is on the S2 RX-8 which is a 3rd centrally mounted oil metering jet. Problem solved. The S1's don't dyno as consistently as a result of this and they don't dyno as high on average as the S2 engines as a result. It is not a synthetic/conventional oil question. Keep in mind the highest source of carbon in the engine (by far) is the fuel not the oil but it all adds up.

 

Oil formulations change so fast that the "issue" they have with one oil could show up or disappear before your next oil change.

It would be nice if they would explain the exact specs that are good or bad.

A well known 0w40 is tested against ACEA A3 standard with 4 different German manufacturers, but is the rotary tested to a stated standard?

Idemitsu is the only oil I know of that is actually advertised for use in the rotary, and it has no test specs, only testimonials.

Even those German car owners can't decide what to use, and they have a severe test spec.

So we all just use what we want, and use longevity stories to decide.

 

There have been engine failures using every type of oil out there. There is always more to the story than gets talked about but many immediately blame the oil and then pass it on. Opinions can be based on this when it may have nothing to do with the failure.

 

Would just like to say that ALL Rotors in EVERY Rotary Engine ever made that uses Petroleum as a Fuel or Gas will have Carbon, Soot or Black Ash or Black/Grey/Beige Crud on it.

I seem to get the impression that the "type" of oil will completely reduce the Carbon Build up inside On rotors...this is incorrect...there will always be carbon present.

Now Hydrogen as a Fuel, that is another story...why do you think Mazda loves it...hey Fred

 

I remember you saying this, and I'm certainly not looking for alternate explanations. I have no doubt that what you're saying is the truth.

I shouldn't have said "the main reason". That was a poor choice of words.

At the same time, I was struck by the obsession on oil change interval, and thought it might be connected. When I brought it in, they didn't ask if I ran synthetic, they asked if I changed the oil often. Which I thought was interesting in light of the later blanket disapproval of syn when I left.

-z

 

maybe this is the wrong place to ask but how does one change from miniral to synthetic, when one can only drain so much out of the system, due to the oil coolers?

 

Most carbon buildup in the engine is the result of GASOLINE!!! Hydrogen would definitely leave a much cleaner motor inside as would propane, natural gas, and even methanol or straight ethanol. Gasoline is just dirty dirty stuff that doesn't burn fast enough to burn cleanly in an internal combustion engine. In an external combustion engine it could be made to burn very cleanly, much like coal can even be made to burn cleanly.

 

FazdaRX_8

You can mix dino and synth oil. Doesnt matter.

Just switch to whatever synth oil you prefer. After a couple of oil changes you'll be 100% synth, in between you might be 90-95%... doesnt matter in the slightest.

 

I had a great conversation with a friend of mine in the oil industry and I was informed that said oil company was given a very firm "Hands off" of the RX8 from Mazda. If you call their tech line they will tell you not to use their products in the RX8.

 

Thanks

 

Is there a reason not to say "Mobil 1"?

FWIW, I've got about 45,000 mi on Mobil1 with a (shudder) 2004 RX-8. If it dies, it dies.

 

Yeah! Mobil 1 0w40, their most advanced oil (Mobil's claim).

Wasn't said "issue" about Mobil's management, not oil quality?

 

There is a certain additive that they use in THEIR synthetics that apparently is cause for concern. They apparently don't use this additive in their conventional oils. I don't know what it is or if anyone else uses it though. It isn't an issue with the synthetic base stock itself. Once upon a time long ago when synthetics were still fairly young, there were issues with PAO based synthetics causing seals to swell. Fortunately it is now understood and is dealt with in the formulations.

 

is this true with all synthetic brands?

 

^^^ no

 

*sigh*

 

The sound of waiting for another RX8 to blow up from using the wrong oil!

 

ok so the Idemitsu Racing Rotary Fuel Lube is half syn/half conventional or whatever the ratio is. I know its bad to mix syn with regular oil, so is this stuff safe to add to the gas or not? I'm using regular oil in the engine and im not sure yet if I want to go mixing the two together.

 

Oh my god ...

wow ... wow ...

 

MMMmmmmm......lol

 

I don't know man ... I really don't know ...

people these days ... *sigh*

 

I switched to Pennzoil 5w30 synthetic (on sale) from 5w30 castrol today, as hot as its been this summer I cant see regular oil hacking it after 3000miles in this heat, Im sure it will burn off fine and as far as the cat an AP midpipe/cobb is in the immediate future.