The topic of Preheating engines has been discussed before but to add a comment or two, here is what I have done with good results. I installed a Wicks "Oil Sump Heater-non thermo. Part # SH2755G page 325 of their catalog. Price was $74.60 Unit designed for the C-65-0200 Unit is FAA approved and is 110 Watts/120 volts. Item is held in place by adhesive so don't forget to sand off any paint and remove any oil residue. Recently started to wrap the cowling in "moving blankets" that I had used when in Alaska and found this really helps keep the top 8-10 degrees warmer than hanger temp. This heater comes in a 500 watt model also but I'm quit happy with the smaller unit. Using a laser non-contact thermometer, I measured 117 deg. surface temp on the heater. It is actually hot to the touch of the hand. Bob