vadym

Should i run 87 or 93 octane in 89 rx-7 N/a?

the engine internals are all stock, and i just wanted to know what will give me a better performance 87 or 93 octane.

NCsublime

People say that lower octane ratings are better for NA FCs, but I tend to disagree. I get 89 and sometimes 91 octane, and I can actually feel a difference in the way it runs when compared to the origanal 87. It seems to run a little smoother, and it may even be a slight bit faster. I'd probably stick to mid-grade, though if I were you (89). You could probably get 91 every once in a while, but getting it all the time in an NA would probably just be a waste. I've no facts to back these claims, but this is what I've learned from my own, personal experience.

-Derek

von

I just started putting 87 in my 89GXL for the first time since I got the car 1.5 yrs ago and noticed imediatly that I got more power.. This is with mods and timing bumped pretty far. Lower octane I would assume would ignite easier wich means faster than a higher rating higher threshold gas. Wich is like raising the timing. I think.

Erik

i'd run 87...mine runs better on it and its cheaper

Crusader_9x

do a search for there was a thread to to long ago where people got really technical and it basically came down to the fact that 87 octane is easier to ignite than 93 is. so for a na 87 will be easier on the motor and therefore you get more power. i believe someone said that if you could get octane ratings down in the 68 range that that is the lowest that the na will run on. but believe me lower is better for na's.

supergoat

I run 87. I noticed it ran better and felt like it had more power on 87 than on 93.