Heating Economics?

Well to clarify the situation a bit, in order to run the heat pumps, the genny has to be set to auto. The genny will then cycle on and off as required to run the heat pumps. To answer one of the other posters, there is no availability of park electric, as I am boondocking. Genny maintenannce is pretty minimal as I do all my own maintenance, and the parts and oil are not all that expensive. I am looking at it purely from a fuel source point of view. Sourcing the 2 fuels is not a factor, as propane and diesel is readily available, although I can run substantially longer between fills off of diesel rather than the propane.