"Jay Honeck" wrote

I know you probably realize this, but your observation makes no
sense. There is no difference in "power" between avgas and mogas.


Actually, there are slightly more BTU's in a gallon of mogas than in a
gallon of avgas.

If an engine was to have its fixed advanced spark too far forward, the lower
octane mogas could produce less power. That is the only way I could think
of, other than a high compression engine that needed the higher octane to
keep from knocking.
--
Jim in NC