My favorite chain saw mechanic (30 years ago) told me that the higher octane fuel you ran - in an air-cooled 2 stroke - the cooler the machine would run, and longer it would last.
I did that until I moved where I couldn't get av-gas easily - but the first several years, that's all that little Jonsered saw!
It is now 31 years old, and the only problems I've had concerned a leaking oiler, and the handle "insulators" wearing out! (looking for them right now!)

I've always been a curmudgeon - now I'm an old curmudgeon.
~Molɔ̀ːn Labé Skýla~