"Newps" wrote

The best setting is whatever gives you the best miles per gallon. You
should find that at around 40% power.

For just building time, MPG is not significant. He wants to stay in the air
for the least gas. For him, I think the old joke, " if that last engine
quits, we'll be up here all day" is probably the "best" he could do. g

I guess the best for him is the slowest speed that he can go, and not put up
with too much aggravation flying the plane. Whether or not that harms the
engine, I'll leave to others much more qualified than me.

P.S. Long taxi times help out, too! g
--
Jim in NC