For reasons I won't go into, I once had access to free AvGas (100 Octane Low Lead). The '49 Chevrolet (235 at the time) ran like crap on it -- didn't like it at all. But ... the '51 Farmall M came ALIVE on that stuff! It would get down and BARK and pull a 2-bottom plow through hard pan like a hot knife through butter. I've heard that AvGas is strictly verboten at the tractor pulls around here ...;)
Anyway, I get the higher octane non ethanol primarily for the boat and the little engines. My friend Milt -- our local Stihl dealer, told me long ago only to use 89 octane non-ethanol in the chainsaws and other Stihl and Kohler engines.
