Originally Posted by fiat84

FYI those (Canadian Polar Pad, Wolverine) silicone oil pan heaters work as per the truck post results below. 125 watt heated his V8's oil(8L?) from -4F(-20C) to +54F(+12C) overnight was proof enough for me to install the same 125 watt model. Went out today -25C and starts up quiet with no cold engine noises.

Oil pan heater results (winter is coming) - Dodge Cummins Diesel Forum
Oil pan heater results (winter is coming)
So I installed a 125watt oil pan heater last week. I got to test it yesterday since it was -4 (F) outside. It kept the oil temperature at 54 (F) overnight ! I was really impressed. Well worth the 10 minute install. The brand I used comes with good install instructions and it comes with the sticky pad already on it. Here are the details of the unit i used:
Model CP154
Size: 2.25 in x 4 in x .075 in
125 watts nominal, 120V

Application Range:
Engine w / 1.5 - 4.5 litres - Oil
Tank w / 4 - 25 litres - Hydraulics
Even though my truck has 3 gallons of oil it kept the engine oil at a decent temperature. The thing I really like about it is that it is very small and easy install.