Mazda rotaries, specifically the Renesis which was unveiled with the RX8 in 2004, are known for their high failure rates.

The failures are thought to result from 2 competing issues.
(1) Excess carbon generation, due to the motor oil injection into the combustion chamber. This carbon causes at least 2 apex seal failure conditions and perhaps one valve failure condition.
(2) Lack of lubrication in the combustion chamber due to lack of oil volume injected.

Solutions to this problem are
(1) add 2cycle oil to the fuel.
(2) effectively bypass using engine motor oil by installing external oil tank and supplying it with 2cycle oil.

The 2cycle oil theory comes from the fact it's made to be burned.

My questions are

(1) any reason(s) to not agree with these outright?
(2) what negative effects of the 2cycle oil injection should be taken into consideration? For example, catalytic converter damage comes to mind.
(3) what considerations should be made in selecting the 2cycle oil.

Any input would be greatly appreciated.

Thanks

I haven't had any rotary engines, but in theory you would at least want a good TC-W3 that has ashless detergents.

Excellent Question. I am running 500:1 ratio, which is about 1 oz 2C oil per 4 gallons gas.

Here is a big thread on the topic

It is a general practice to mix oil and fuel for 2 stroke engines and the same can be applied to rotary engines.

The onlt thing you have to make sure that the fuel and lubricant are mixed thoroughly. In addition check the mixture for lubricant / aditive seperation on storage at lower temperatures.

In my perspective mixing Oil with fuel is better, because you should not worry about the function/failure of oil injecting system. It is more fool proof.

You may use oil that exceeds JASO FC requirements