"Jay Honeck" writes:

Huh??? On my 230 hp O-470, I cruise at 23-squared, without any fancy
engine monitors. Using the "pull-until-it-feels-about-right" method of
leaning, I get 12 gph.

I can lean to that fuel flow without any undue engine sounds, too. But my
EGTs go well over 1500 degrees, and my CHTs push 350 when I do.
I would rather burn a bit more gas. [...]

OK, but that brings into doubt your assertion about your fueling style
being a big cost savings, doesn't it? Using 25% more fuel at 70% of
the cost per unit volume is only about a 10% savings. Or maybe you
didn't lean aggressively on avgas either?

- FChE