Your opinion and advice please: Coming from the tropics and after time in Canada and now at 7,000+ ft elevation in the North West I am considering the features and advantages of oil / coolant / battery heaters.

My instictive feeling is to have the oil at something above the freezing temperature of water (40-50 degrees F) and not necessarily the coolant. Sensible idea to in any case have the battery also at about 50 defrees F.

Anyone experiencing leaking coolant from the heater plug insertion?