Frank Thompson wrote, on Tue, 02 Sep 2014 03:15:28 -0700:

If I use high octane gasolene w/o alcohol in my small engines is it ok
not to use any of the various stablizers? How long will the high octane
be safe to use w/o the stabilizer?

Not sure where you are, but, in the states, we measure the anti-knock
rating using a combination of the research and motor method, and then
average the two, to come up with the anti-knock index, e.g., 87AKI.

It's rare for a small engine, I think, in the USA, to be designed for
a great anti-knock index than that "Regular". As you know, putting
a gasoline of higher anti-knock qualities than designed into *any*
engine which is both already running properly & not subject to excessive
heat and/or loads, can provide absolutely no positive value.

Summarizing that as saying that the octane rating is designed into the
engine and most "small engines" are designed for 87AKI here in the
states, why would you even *want* to put gasoline whose flame front
moves slower (so to speak) into an engine, unless it's designed for
such fuels?