This report presents a detailed estimate of the labor and energy, by fuel type, required by the U.S. economy to remanufacture gasoline-fueled automobile and truck engines. Th estimate was obtained by combining data provided by several remanufacturers with the results of input--output analysis. A rough estimate of the labor and energy required to manufacture new engines is also given. These estimates suggest that remanufactured engines require 50% of the energy and 67% of the labor that new engines require.