I have a O-360 and if you look at the Lycoming manual you can have
different settings for the same power and save fuel one compaired to the
other. Usually it is the MP over the RPM that gives you the better fuel
burn.


-------------
Regards, Ross
C-172F 180HP
KSWI


Jose wrote:
The 75% "Best Power" and 75% "Best Economy" couldn't both be
actually 75%, could they?

Yes, they could. You are using more gas at the 75% best power
setting than at the 75% best economy setting.


Sorry, I mean they couldn't both actually be 75% for the same MAP/RPM
combo.

The leaner setting would have to be developing less power, wouldn't it?


The thottle and mixture levers may be in a different position in order
to achieve the same MAP/RPM, as a result of using the fuel more or less
efficiently.

Jose