The author of "The Killing Zone", which is an analysis of significant flight safety factors, advocates the use of constant carb heat when cruising in high risk conditions (high humidity / precipitation).
Experienced and diligent pilots are still troubled by carb icing. With the consequences being potentially so serious, Whirlybird raises the most important question. What are the penalties for engine and fuel??
I would imagine the power loss can be guesstimated being roughly equivalent to rpm lost.
I suppose the hourly fuel burn is about the same, but you just go a tad slower.
If using carb heat in the cruise gives you an overly rich mixture, does that meaning leaning would be more important?
I have heard a number of well respected pilots who think constant carb heat in the cruise is reasonable practice.
Awaiting further guidance,
Justin