Is there a 'safe' octane range for our engines?

[Centauri]

Just curious.

Locally, the best stuff available is 91 (or even 90...) with 10% ethanol. Lately I've started adding Royal Purple booster to compensate. But in other markets I know 93 is available. I know going too low can end badly, but what about too high? 93 and the +3 RP booster?

Just wondering before I ever get myself in a pickle.

[SgtMarshal]

I wouldn't bother with the royal purple octane booster, it is likely just snake oil. if you want to add stuff to raise the octane, get some torco accelerator. it will actually raise the octane legitimately, not like the snake oil type stuff. you would be just fine with premium though. if it was a big issue, the car manufacturers would be going rounds with the gas companies. the highest octane available where I live is 91 as well, and the owners manual dictates premium fuel only.

edit for link added: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Scottydoggs]

depends on if you have kr with your mods. if you do running 91 and dont when running 93 you know your tune needs to be adjusted for the 91, aka less timing up top would fix this.

or get on marshals torco bandwagon.....

[SgtMarshal]

I was curious what was in that royal purple to raise the octane, and it's mmt, which is not effective.

[J57ltr]

I octane requirement goes down as altitude increases. That's why some places don't have 93-94 octane.

[SgtMarshal]

I octane requirement goes down as altitude increases. That's why some places don't have 93-94 octane.

I don't think that is accurate, I think octane becomes more necessary as elevation decreased. More cylinder pressure at lower elevations

I misread what you posted, we both said the same in opposite ways

[J57ltr]

Yeah. This is why when you go to Denver or Utah they have 85,87,91 but you come to Houston or anywhere below 1000' or so they have 87,89,94.

Jeff