New materials and energy problems are increasing the feasibility of using flywheel energy storage systems to power personal automobiles. A promising concept appears to be the combination of the high specific power density of a flywheel with the high specific energy density of a small heat engine. A technical and fuel economy assessment of a small personal vehicle powered by a hybrid flywheel/heat engine drive system is presented. Technical evaluations indicate that a flywheel/heat engine system based on improved materials technology could serve as a practical vehicle drive. While somewhat limited in performance, the proposed system could produce significant improvements in fuel consumption rates. Technological advancements in materials and power transmission systems would make flywheel/heat engine systems even more attractive.