Those living in rural areas with a need for a fairly light oil without too much contamination, could do worse than to ask their local farmers about their used tractor oils, some of the newer big and fancy tractors hold as much as 30 gallons of thin oil in the back end which needs changing at 1500 hour intervals, on large farms this adds up to a lot of oil. One of the problems I have found but thankfully quite rare, is getting a 45 gallon drum home only to find its half full or more of water. Some of the oil has hardly needed thinning before use and in my view is is a superior alternative to WMO as a diesel substitute. Not tried it in a Lister yet but both my Perkins 4-270 D genset and IH 3434 tractair love it with only a little more smoke than when diesel fuelled.
Mark.