The well-to-wheels assessment is widely used in the automotive sector to analyze the efficiency and competitiveness of different powertrain/fuel options. The paper proposes a global index that takes into account both the energy and environmental aspects on an uniform basis, through the assignment of the costs associated to the energy and to the pollutant emissions. The European market is analyzed and other pollutants (NO,,. PM and SON) are added to the traditional well-to-wheels evaluations (energy and GHG). The proposed well-to-wheels global index offers a useful place-list that takes into account both energy and environmental aspects and, at the current market conditions, it results that the energy cost prevails (70-85%) over the environmental costs, and among the analyzed external costs, the main contribution is due to the GHG emissions. Natural gas-derived fuels seem to be the most promising. The global index for battery electric vehicle from a European mix are closely linked to the driving range. Conventional biofuels are very critical at present, while significant improvement of the well-to-wheels global index is foreseen for when new generation biofuels will be mature (2030 forecast). In short, even though the proposed global index is not an exhaustive index, it could be a useful tool for decision makers. (C) 2010 Elsevier Ltd. All rights reserved.