For no particular reason, I was browsing through the Continental Engine Maintenance and Overhaul Manual (M-18) for the TSIO-550 family of engines.  The engine specifications are listed on pages 2-22 through 2-33.  Each of these engines has a "Minimum Cruise RPM" of 2300 RPM.   I was unaware that there was any RPM restriction (other than max. RPM) on these engines.

I never go that low.  My minimum cruise RPM is 2400.

Does anyone use a cruise RPM below 2300?

Barry Knotts
LIV-P, N4XE