What 's a good engine oil, to get more life and make a rotary engine last longer that doesn't cost you an arm and a leg.

 

royal purple is good, also amsoil. ive been using castrol gtx

 

Read:
https://www.rx7club.com/forum/showthread.php?t=801575

 

The good thing is most rotaries never have an oil-related issue ever.

So with that backdrop that means there are a million opinions about the best oil, and even highly experienced engine rebuilders can't agree on synthetic vs. mineral.

IMHO, especially on boosted rotaries, it's better to change often than spend a lot on the oil. Reason being fuel gets pushed into the oil and drastically lowers viscosity long before an expensive oil "wears out". Even still I continue to use Mobil1 because it's reasonably priced for 5qts/$22 at walmart. Given the fuel dilution I see on my car I'm never going to buy Royal Purple or Amsoil or any of those $11/qt oils. I should probably go back to Castrol GTX.

If you're going to be fussy about fluids, I recommend draining and replacing your coolant every year. Do not flush; just drain and replace with antifreeze and new distilled water. Unlike oil, poor coolant condition will kill a rotary engine.

 

mobil 1

 

castrol gtx made my engine run real smooth

 

Thanks guy's for your advice on oils,il drink a beer 4 you's

 

in the factory manual it says to never use synthetic oil. i use royal purple

 

some synthetic have been proven to work good with rotaries.

 

ya, i just read the link that aaron cake posted. i found that it said that because of when it was made how synthetics werent as advanced as todays synthetics

 

from my experience mobil 1 10w-40 or valvoline vr-1 20w50 is good

 

I use Idemitsu. Good stuff. It might be a little more expensive but how much more is that per year? $50-60? No biggie.

I also put 4 oz of idemitsu premix per tank, and occassionally some MMO to clean it out some.

No smoke, purrs like a tiger kitten even at idle.

You gotta remember the whole "no synthetic" thing was written like 16 years ago. Idemitsu is an oil specifically designed for the rotary engine, and it's synthetic.

 

MMO is just "wax mud" as Icemark liked to put it. Check the datasheet for ingredients.

Oil is one of those things that for some reason is always a debate. I don't know why, because every oil on the market meets the same specs. I buy whatever oil is on sale and always have.

 

Did some reading on MMO.

It seems the flash point is around 174 degrees according to the MSDS sheet on it.

That means its basically worthless as a lubricant in engines I would guess, but I wasn't talking about using it as a premix. So, anyone using it as a premix I'd be careful lol.

OTOH the materials in the mmo should do some cleaning of engine internals, that's primarily what I was using it for.