A segment- and fuel-disaggregated analysis of the production data of the new European vehicle market during the last decade helps to understand the sharp increase in average weight, and to introduce an indicator linking CO2 emissions to a vehicle's unit of weight. Using this indicator, simulations are made to calculate the average CO2 emissions if the average weight had stayed constant from 1995 to 2005. If the weight had remained constant, the 2008 target of 1998s voluntary agreement (VA) would have been met, and the recently approved regulation would probably have been unnecessary. Then, CO2 emissions are projected to 2015 using different vehicle characteristics and market penetration. Five scenarios have been introduced to study the different opportunities that could arise by 2015, including a backcasting scenario showing what is needed to reach the goal set by the recently approved EU climate package regulations. The analysis concludes that powertrain technologies alone are unlikely to bring the sufficient break in trends to reach set targets. Acting on average weight, through unitary vehicle weight or segment shifting, of new vehicles is key in reducing the average CO2 emissions in the short and medium term. (C) 2009 Elsevier Ltd. All rights reserved.