Abstract: A device for increasing the fuel efficiency in an internal combustion engine having a fuel supply conduit connecting a fuel supply and a carburetor, a hollow housing disposed in fluid communication with the fluid supply conduit between the fuel supply and the carburetor or firing chambers. A heat source, such as a heating element is mounted within the tubular member for heating the fuel flowing through the hollow housing. While flowing through the housing, the fuel is in intimate contact with metallized pellets of a metal, such as a noble metal deposited on a substrate. The pellets are disposed within the housing. In an alternate embodiment, hereof, two types of catalyst are disposed within the housing, one richer in metal content than the other. In practicing the present invention, the fuel passes through the housing and issues therefrom at a temperature less than 100.degree. C.