I completely understand when many say that if such and such oil meets certain standards (that are acceptable to Mazda per the owners manual) then ANY lubricant should be good enough for the Renesis.

Logical.

But many miss the point. The key is LONG TERM. Castrol Syntec MAY be fine in the SHORT TERM. I say MAY because no one has convinced me yet that sythetic oil doesnt do damage on molecular levels that will only surface after prolonged use.

Until Mazda (or anyone for that matter) does LONG TERM TESTING of synthetic oil on the Renesis engine, NO ONE knows the effects.

That said, I think it is irresponsible for anyone to advocate the use of synthetic oils in the Renesis engine until such data is available. When in doubt refer to the manufacturers statement.

"The long-term effects of synthetic oil use in the Renesis engine is unknown and therefore mazda does not recommend their usage."

 

Wow. Your statement clears everything up for me now.

 

i believe racingbeat has done long term or is doing long term effects of synthetic in the renesis...

i dont really get the point of this thread...
but if you wanna btch about it, just dont use it.
other people live and die by synthetic, and companies have already done testing and concluded i believe that swelling is not an issue in our cars.

 

MANY MANY MANY MANY race teams have used syn oil in their engines that are run at WOT (wide open throttle) for hours every weekend. Also MANY MANY MANY MANY rotary owners have used syn oil in their daily driver and street legal cars for years and thousands of miles....and those were in roatry engines that had seals that were not compatable with syn oil.

We have a motor the IS compatable with syn oil....the only thing that is holding mazda back is the fact that they [mazda] dont know just how complete the syn oil with burn, and worry of 'gunk' clogging up the emissions system as the motor is oil injected. This is mostly due to the more strict laws in the US and other parts of the world on the life-span of the emissions systems, and also due to the fact that not all RX8 owners drive the car in the upper RPM range, that means the EGT (exhaust gas temps) might not get hot enough, or hot long enough for the residue from the oil to burn completly.

This motor will do FINE with syn oil, long and short term....how the emissions system (catalytic converter and o2 sensors) hold up is yet to be seen.

On that note I will tell you that its not 100% known....but id gladly replace my cat every few years and have a motor with little to no wear on it after 100k miles.

Going by what your saying : very few manufactures do long term testing with syn oil...even then its only on a few models in their lineup. Are you saying that any car that doesnt COME with syn oil should not use it until there is data to show its ok. Ive run syn in every one of my familys cars. Not a single problem yet, and bettween all the cars there has to be around 200k miles on syn oil.

Mazda has said themselfs that the internal seals ARE compatable with syn oils.... and we know that iron, aluminium and other metals in the motor are compatable with syn oil....so there is really no reason it would do any harm to the MOTOR, just the possible early failure of the emissions system componets.

 

Also you should thank myself and other members as we are doing the long term tests, day by day, mile by mile.

 

THANK YOU

 

If you had put one more MANY in there I would've believed you. Since you didnt, your data is incomplete.

Opinion there.


Exactly! AND any other components the oil touches.


Is that what syn oil does for an engine? Hmm.. I guess advertising really does work.

If the manufacturer doesn't use it or call it out specifically, there is no need for it, a waste of money, no added benefit AND possibly harmful. Take your pick.

Again, sounds like opinion. Mazda said? Do you have any corroborative documents available?

Hey whatever floats your boat is fine. But remember there are impressionable people here. Alot of what has been discussed recently on this forum has been factless opinion. What I'm advocating is not to believe the hype and to err on the conservative side.

 

API certified 5w20 is what my manual says. No mention of synthetic not to be used.
As long as the syn meets the requirements all is good.

 

This was in your new owner package.

 

Actually it was not included in mine (July 2003 delivery).

But consider this - what are the requirements for RX-8s outside the US? Hmmm, 5W30. WAIT! Isn't that brochure gospel? Why do dealers in the UK and Europe use synthetic oil in their dealer services? Why do they use different viscosities? Why are we such sheep that we won't question a brochure written by Mazda's North American liability lawyers ?