Going into my first winter (hangared in NJ) since buying the 231.   I won't be flying much over Dec - Feb and want to do the best for my engine.  Mike Busch says "using an insulated cover and a multipoint preheating system that is plugged in continuously is one of the most effective methods of eliminating internal engine corrosion, particularly if the aircraft is kept in an unheated hangar rather than outdoors"  ("Engines", p.255) Continental on the other hand specifically has a warnin