Re: Overpropped; What to do?
In quoting me you dropped the word "overall". This term is to encompass efficiency related to
1. maximum range on available fuel.
2. a level of RPM that causes above normal wear on the engine.
3. time to destination.
4. maximum torque.
5. hull speed.
An over propped engine ends up operating at a higher manifold pressure, resulting in a more frequent, destruction of head gaskets.