ACRx7-85

What octane should I use in my 1985 RX-7 12a carb engine? 87 / 89 / 93

zyounker

lowest you can find.. actually the lower the better.. It will make better power with lower octane gas.


-Zach

Manntis

octane can be described as resistance to detonation. In higher compression engines, including turbocharged, a higher octane is desirable to prevent pre-detonation that can cause engine damage. In a low compression engine such as a normally aspirated 12A rotary, a lower octane such as 87 will actually offer better performance.

Edit: So, yeah... basically what Zach said

12abridgeport

Does that mean i would actually get a better advance on a 12a bridge if i have a low octane gas? I always used the highest.

fatboy7

Not better advance, in fact timing advance might decrease, but the timing where peak torque occurs will produce more power than higher octane. It's more to do with flame propagation, than anything else.

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