Using the fuel that gives you the most work for its cost is one way of trying to get the most from your farm fuel dollar. But you also should consider costs equipment and problems of handling the different fuels.
Hull, Dale O.
"What Fuel for Your Tractor?,"
Iowa Farm Science: Vol. 18
, Article 3.
Available at: https://lib.dr.iastate.edu/farmscience/vol18/iss3/3