100LL aviation fuel is the fuel in question. It was supposed to be replaced with lead free fuel by 2010, but it's still around today; see linked article. Some aircraft engines require 100 octane gas. Anyway, it's a waste of money in a stovebolt engine. If ethanol is the worry, some of the premium gas is ethanol free. Check gas buddy for a gas station near you that has ethanol free gas.
https://www.eaa.org/eaa/news-and-pu...-100ll-unleaded-replacement-complexities
