Yes, they did. Read your Owner's Manual.

 

http://www.rotaryheads.com/PDF/RX8/0Owners.pdf
Text search for the word "synthetic" actually doesn't exist in the owner's manual.

Page 234 has the recommended oil

And even searching for all 116 occurances of the word "oil", and going hit by hit, there is no reference.

( On the other hand, there are a dozen+ warnings to check the oil frequently because the engine injects some )

 

I believe later editions of the owner's manual say no synthetic. Mazda must have some kind of a time shift in play when they use that to deny warranty coverage to the years where the manual doesn't say anything.

The OM for my '06 does not say anything about synthetic, but the supplemental DVD that came with it does.

Ken

 

Do not use synthetic oil is an incorrect translation. The original Japanese says that the use of a synthetic other than genuine Mazda Synthe-Renesis could cause starting performance to worsen.

 

I own a 2008 40th anniversary edition RX8 and in BOTH the owners manual AND the DVD that came with the RX8 it specifically and officially says DO NOT use synthetic oil or semi-synthetic oil in the car.

 

My 2006 manual I recall stated that it did not recommend but did not state "do not use" for synthetics.

 

For those that care...

2004-2006 manuals do not specify about using synthetic oil, starting in 2007 is when it is included in the manual. In case it doesn't automatically take you there it's pages 286 for the 06 manual, 295 for the 07 manual.

2006: 2006 Mazda RX-8 | Owner's Manual - Page 286

2007: 2007 Mazda RX-8 | Owner's Manual - Page 295

 

Are we still debating this?

 

dead horse

 

Not really. There is a question on Mazda's apparent uncertainty of the recommendation/prohibition, but anyone that actually understands the true reasons/causes/etc... knows that Mazda's wording in the manual doesn't mean jack. The other people that believe that the engineers are the ones that wrote the manual think that there is still a case against synthetics.

 

True that.

/thread

 

as long as rotaries exist this will be a never ending battle

 

This x 100

 

We're not debating it. We're just remembering and talking about it. Much like we do with the moon landing, Babe Ruth pointing to center field, the long count, hanging chads in Florida, etc. It's just part of the collective conciousness.

Ken

 

LOL...I had to look up the "Hanging Chad" reference

I'm Canadian...

As per the OIL thing....It's oil Not Enough is a Problem...other than that it really isn't an issue

Most oil these days is at least part "synthetic"....you don't get unadulterated Dino oil much anymore

 

Hey the original poster never gave a final update if he got his engine replaced under warranty. The only issue in this whole oil debate is whether or not Mazda can legally deny coverage for synthetic or semi-synthetic oil use. Legally in the US they can't but sadly they have tried to deny folks over the years. Just never give up on this point and keep full oil change records and you can win on this front.

 

If it matters, the above posts that show that the 2005 manual (which the OP has a 2005) doesn't expressly prohibit it, so no, they can't deny the warranty.

The 2007+ they legally can, even if it is completely unfounded, as they would win in a court case simply based on what is said in the owner's manual.

 

There is still a case against most synthetic oils just not against a 0w30 synthetic oil. This is well documented by Idemitsu. 0w30 is an exception.

Rather than prohibiting synthetic oil and then allowing exceptions Mazda should only allow a 0w30 synthetic oil and prohibit all other oils. Therefore the 0w30 oil which was the exception now becomes the rule.

 

There is no consumer oil commonly available that IS NOT a synthetic.


And it doesn't matter anyway. Stop injecting 4-stroke oil, change to injecting 2-stroke, and it doesn't matter what the hell people think "synthetic" oil burns like. NO 4-stroke oil is designed to burn well.

 

No owners manual can prohibit the use genuine Mazda parts such as 0w30 Synthe-Renesis oil.

 

Legally, yes it can.

Practically, none of them should bother trying to add a distinction.

 

I have been using 100% synthetic with my 2004 since 2010 when the reman was installed. First 1200 miles or so used regular oil. Switched to synthetic when the turbo kit was installed.

 

For anyone else that wants to argue that synthetic oil generates more carbon buildup... Take a guess where the oil injection is, and then see if you can guess where the rest of the carbon buildup actually comes from.



I still advocate a SOHN adapter for Series1 (this is a Series2 rotor), because 2-stroke is still superior for burning, but even the worse 4-stroke synthetic oil is still cleaner than gasoline.

So perhaps the prohibition should be against using gasoline in the engine, not against using synthetic oil.....

 

First off, why would anyone tell them you use synthetic? Don't ever volunteer information. There is no way for anyone to test what a used oil was originally so don't be scared of that.

I spoke directly with the Mazda engineer who wrote the recommendation in the manual back at SSVIII. Incidentally he also formulated Idemitsu for the 787B. Zoom44 was there too. We've stated precisely why they stated on paper what they did. It's been stated multiple times. I have no idea why no one wants to listen? There is no one in the world who is more trustworthy on the matter. Look it up.

 

I listened, if that makes you feel better. I don't use synthetic myself, but for reasons other than the various belief systems discussed here.

I think people have gotten snagged when they produce oil change receipts and one or more says "synthetic."

Ken