Sorry if this has been discussed previously, but I'm curious as to why Mazda recommends premium for the RX-8 when all previous NA rotaries have only needed regular, and I seem to recall some talk of the engine performing better, under certain circumstances, with low octane. Someone told me the Mazda factory racers used to use a special racing blend with an octane rating of about 80.

I know there may be any number af reasons to use premium in the new engine design... just curious as to what those might be.

I read somewhere that a 12A could run in 70 octane!

Ignition timing is probably highly advanced compared to earlier rotaries. Hence the need for higher octane.

The press kit also states the Renesis has a 10:1 compression ratio. I believe that usually requires premium to prevent detonation.