Multifunctional Fuel Additive Package is used for power generator engine applications of furnace oil. The Fuel Additive Package provides effective remedies for during combustion as well as post-combustion problems encountered due to contaminants present in furnace oil. The Fuel Additive Package reacts with various other contaminants in the furnace oil during combustion and change composition of the ash. The Multifunctional Fuel Additive Package raises the melting point of the vanadium compounds such that they become non-adherent and non-corrosive to high temperature surfaces.