An assessment is made of on-the-road performance, for a pure hydrogen fuel cell car, a pure battery operated car, and a hydrogen fuel cell-battery hybrid car. The tool used for this study is the modular software-package ADVISOR [Markel T, et al. ADVISOR. J Power Sources 2002; 110:255-66], which is well tested and offers a range of simple, parametrized sub-models or more detailed physical models for the fuel cell stack, the batteries, the electric motor, the exhaust control, the transmission and entire power train including controls and control strategies. The basis configurations of the cars modelled is characterized by high energy efficiency, before adding a fuel cell and electric motor also of high conversion efficiencies. Preceding the presentation of results, the best way to characterize energy efficiency is discussed. (C) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.