Originally Posted by SkySkiJason
As far as the tank goes, I prefer a 'heated sump' design. The idea is to heat a small amount of oil where it will be sucked out of the tank. The problems with heating the whole tank include expedited polymerization rate, increased condensation and obviously its just terribly inefficient. The typical 'heated pick-ups' are heating a column of oil, then pulling the coldest oil in the column from the bottom of the tank. A heated sump with limited communication to the main tank can primarily heat a much smaller volume of fuel, while heating the oil in the tank above it enough to allow it to run into the sump in the coldest weather.
Also, heating the whole tank makes it expand and contract and can crack the welds on the tank. I believe this is why my tank got a crack.