Change to the holding airspeed appropriate for the altitude when 3 minutes or less from, but prior to arriving at, the holding fix and set appropriate power …

Instrument Rating Airplane ACS › III. Air Traffic Control (ATC) Clearances and Procedures › B. Holding Procedures

Change to the holding airspeed appropriate for the altitude when 3 minutes or less from, but prior to arriving at, the holding fix and set appropriate power as needed for fuel conservation.