Apollo 250 92 octane or higher?

Quokka42 · 09-30-2023, 09:17 PM

As noted, American 87 is approximately the same as 91-92 RON. The American number uses an average of static and dynamic octane ratings from when that mattered, the blends in modern fuels mean RON is just as accurate.

I am running 91 RON in my son's bike, but I am running an iridium plug, which is slightly colder than stock. While theoretically a higher octane fuel will give slightly less power we found it is not noticeable - I initially ran 98 as I didn't know what it was rated for or the compression ratio.

I run my road going vehicles on E10, especially air-cooled, but never use it on off road or marine even with stabiliser. My experience is the stabiliser "wears out" and it gels, clogs, etc. If you suspect you have had some ethanol in there, try pouring a good slug of acetone in the tank - old racer's trick, it dissolves a lot of stuff, including recombining alcohol, raises octane rating, and it ignites more easily.

09-30-2023, 09:17 PM	#1
Quokka42 Join Date: Sep 2023 Location: Melbourne Australia Posts: 5	As noted, American 87 is approximately the same as 91-92 RON. The American number uses an average of static and dynamic octane ratings from when that mattered, the blends in modern fuels mean RON is just as accurate. I am running 91 RON in my son's bike, but I am running an iridium plug, which is slightly colder than stock. While theoretically a higher octane fuel will give slightly less power we found it is not noticeable - I initially ran 98 as I didn't know what it was rated for or the compression ratio. I run my road going vehicles on E10, especially air-cooled, but never use it on off road or marine even with stabiliser. My experience is the stabiliser "wears out" and it gels, clogs, etc. If you suspect you have had some ethanol in there, try pouring a good slug of acetone in the tank - old racer's trick, it dissolves a lot of stuff, including recombining alcohol, raises octane rating, and it ignites more easily.
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