NON ethanol 91 octane if at all possible. If in an area we absolutely need gas I search out anything non ethanol and only run ethanol as a last resort and only what I know I can burn out asap. Run this in all of my vehicles as well and small engines. I used to run 89 ethanol in everything until about 2 years ago and no matter the brand had issues with every single small engine carb I owned and found it was the gas going bad within weeks causing carb issues, switched to 91 premium in everything and all issues disappeared.
Talked with several small engine guys and they tell everyone to run nothing but non ethanol gas and 91 premium if it will not be used within a month.
Ethanol goes bad and starts to deteriorate within a month.
Lower octane non ethanol has 60-90 day shelf life.
premium has to by mandate be good for a 1 year shelf life.
I know of a lot of people in the aviation and municipalities who add a mixture of avgas to regular gass to extend the life indefinitely as avgas has a higher mandate against deterioration and moisture absorbtion and lasts a very long time.