Tony wrote:
There's the other point: isn't glide range extended in a 172 if the
prop isn't windmiling?


It is in any aircraft.

Stefan

You'll start another windmilling argument with that. There are
some serious divisions over whether to stop a prop or not to get more
range after an engine failure.
When we stopped the prop on the 150, the airplane's attitude was
more nose-down to maintain the same glide speed, and the rate of
descent was higher. The theory here is that the much higher angle of
attack on the prop blades when stopped causes more drag that if it's
windmilling.

Dan