Hey everyone,

I've been doing some research for this and I'm still confused. The manual for the FD states that synthetic oil is bad for rotories and shouldn't be used. But then I did a search and people on the forum are suggesting to ONLY use synthetic oils like Mobil 1...

who's right??

also, I'm going to be flushing my car out with new everything right now.. which brands are the best to use for diff, transmission, motor oil, and oil filter???

thanks
mike

 

Do a search on "synthetic oil" there was a HUGE HUGE arguement on it.

 

Answer 1:
This has been discussed a lot on this forum. One thing is for sure though, no one has had an engine failure becasue of a synthetic.

Answer 2:
Mobile 1

SEARCH AND READ NEXT TIME!!!!!!!!!

 

Also check the Rx8 forum. This is a hot topic over there and a couple people have corresponded with mazda's customer service department about it.

 

i used mobil1 sythentic for my diff and tranny fluid.. works great. smooth out my shifts ALOT. if you can get redline MTL then i would reccomend that for your tranny fluid... if not.. mobile 1 or RP

 

I use regular oil because it is made to burn a little. Sythentic is made not to burn, I still use Mobil products and I like them. I change the oil every 1500-2000 miles so that is another reason I dont use sythentic. as for pros and cons I really dont care. I just know that mine runs fine.

 

mineral oil for a break-in process, then synthetic after that.. royal purple would be my choice for syn..

 

And no one has had an engine failure because they used regular oil either.

If you drive normally, changing with regular oil every 3K miles/3 months is just fine. I've been using Castrol GTX in all my rotary cars for years without issue. As for tranny, diff. fluid, and oil filters, I use regular Valvoline gear oil and Mazda OEM filters. Regarding the former, some people with bad synchros or other transmission issues find that synthetics smooth out their shifts, others report no difference. IMO, synthetics are overrated. That's not to say that they aren't useful. I just feel in the long run, they don't offer any real benefit over the regular stuff and isn't worth the extra money.

 

Redline says they've used their synth. oil in rotarys from day one without probs. I think how often you change your oil and filter means more than the type (except for a Safeway brand or something, don't use that!)

 

I have yet to hear of any rotary motor, even a racing motor, that had wear or failure issues due to the fact it had dino oil or synthetic oil in it. Only oiling issues I have ever seen were due to loss of oil pressure.

Fact is when the motor or turbos go it will be from something other than the oil

FWIW I run Castrol 10W-30 motor oil and change it and the filter every 3000 miles or every two race events; whichever comes first. That's still a very conservative schedule for a modern oil. Mazda recommends changing the oil every 5000 miles for normal use or every 3000 for aggressive use. The only reason I change early if I have raced the car twice is to be certain the oil isn't dilluting due to fuel, but honestly I haven't had that problem with the new motor (now 25K on it). My car is still on the original stock turbos with 125,000 miles on them and the shaft play is still well within spec.

I run NEO synthetic in the trans and diff. I haven't tried anything else but have really liked the NEO. If it's good enough for a bunch of race teams it's good enough for me (but it's pricey!).

 

True!

Your best reliablity mod is no mods. Well almost!

 

I have always heard that rotaries burn oil so if you use synthetic it doesnt burn completely and builds up eventually and snags the apex seals and causes a blown a motor whereas regular oil burn completely i use castrol gtx as well.... and a very important mod for oil is the thermal pellet you can get an aftermarket one from atkins for 8 dollars and they replace the stock one whcih fails frequently and causes loss of oil pressure very good idea for reliability

 

Here is More Than You Ever Wanted to Know About Motor Oil

 

Ignore the above, some synthetics are made to burn.

 

Even if it didn't burn...

Does the engine need to actually burn the oil? Or does it just need to lube internal componenets?

If it is just a matter of lube, then burning is not an issue.

 

Some people once "heard" that the world was flat, so it must've been true...

 

What?! The world isnt flat!?

 

I use Crisco.............

 

people are too paranoid.

 

 

Ouch. With 614 posts you should have read by now that rotaries burn engine oil with the gas. Or have you just been looking at bodykits for almost 3 years?

 

I dont think he was asking, just stating or talking out loud.

 

I guess so, but when you are in a rotary engine forum, discussing engine oil, why do you even need to ask?

 

20K miles so far on mobile 1, without any problems, leaks, or failures what so ever.

 

Random question:

Does unburned synthetic oil in the exhaust gas affect the cats at all?

(Mobil1 10w-30 user)