91 octane gas is destroying my engine. It knocks so bad. I have a 93 rx7 mazda service manual that says fuel specification unleaded premium(ron95) or higher. Where do they sell 95 octane gas?

 

US gas is rated differently. I think it is RON + MON / 2

It is unlikely that your car would still run if it was knocking that noticably. It is very likely that something else is wrong, or that your perception of knocking is incorrect.

-Max
>400RWHP on 91 octane CA pump gas

 

Every street FD in California runs on 91 which is the highest octane gasoline you can get, and yet, your car and your car alone detonates??? It's not the gas unless you pumped 87 by accident. Something is seriously wrong w/ your car. What are your mods, and how much are you boosting?

 

Yep something is wrong with your car. I dailey drive my stock Fd with 89 octane with no problems at all.

 

**** some water or sea foam through the intake and see if you can get rid of some carbon.