Mxsmanic wrote:
chris writes:

Are you perhaps pulling the RPM back too much and seeing a decrease in
airspeed?

The redline RPM is about 2500, and I pull it back to about 2000-2200.
My IAS then drops by 10 kts or so. The engine is less noisy. I don't
adjust the throttle (which in most cases is fully forward) or mixture
(adjusted for slightly ROP). The fuel rate drops a lot with the RPM,
but the manifold pressure doesn't seem to move much, or I haven't
looked at it closely enough.

Takeoff and landing of course are with the prop set to full fine

Yes, for take-off and landing I make sure the props and mixture are
set fully forward again.

Manifold pressure is set by the throttle.. And you need to pull the
throttle back before pulling the prop control back, and vice versa for
increasing RPM