A composite boiler tube has a fireside surface and a water-side surface and comprises a metallic tubular member having an outer surface and an inner surface. One of the metallic surfaces has an efficiency enhancing coating adhered thereto and providing the composite tube with the fireside surface or the waterside surface. A method of enhancing the efficiency of a boiler tube which comprises a metallic tubular member having an outer surface and an inner surface includes the step of applying a coating of efficiency enhancing material adhered to one of the metallic tube member surfaces, thus to produce a composite boiler tube.