What's with the 25-squared recommendation for climb in an Arrow? (Lycoming IO-360C1C6). I don't see anything like that in the POH but my instructor insists on using it for climb. But this brings the climb rate so far back it's pathetic. Aside from being quieter with lower RPM, what is the reason for this? I have read John Deacon's columns on Avweb and he has collected data that even flies in the face of the old "keep-MAP-lower-than-RPM" rule of thumb. Thanks!