In article yLqec.18880$rg5.39150@attbi_s52, Ben Jackson wrote:
Is the answer that the constant speed prop is slowed down because we
*can* and the fixed pitch prop is just suffering all the ill effects
you'd expect, like higher wear, more noise and frictional losses?

Yep. Just like if you've got a car with a 5th (or 6th) gear, you'd use
it on the freeway instead of 4th. You can still make the same power in
4th but your car will be noisier and use more fuel.

The Bo I used to fly I would typically use 2300 RPM which seemed to
provide the best compromise of power (and cruising speed) to fuel flow
and noise. The difference in noise was dramatic in that plane between
2600 and 2300.

--
Dylan Smith, Castletown, Isle of Man
Flying: http://www.dylansmith.net
Frontier Elite Universe: http://www.alioth.net
"Maintain thine airspeed, lest the ground come up and smite thee"