I had a 415-C with a Tanis heater. The Tanis is probably the best engine
heater. It heats the cyl. heads and has a heating element to heat the oil sump.
It is not a fast heat system. If you can plug it in the night before your
flight it will have the engine nice and warm. At the least it will take about
two hours to have the engine ready to start. I do not have a Tanis on my M-10
so I use a 'dip stick' oil heater. These are sold at auto parts stores and can
be bent slightly to fit the oil sump a little better. They don't heat the
cylinders but do at least get the oil warm. This takes about 30 min. Here in
Minn. I generally don't fly unless the temp is 20F or above. Temps below that
are just too hard on the engine.
