A study was carried out to identify and analyze the possible fuel economy improvements in the European passenger cars. A compliance with the today (1975) European exhaust emissions regulation and undiminished performance in comparison with the 1974 vehicles were the main constraints within the study was conducted. Hardware which can be in production by 1980 - 85 was considered. A statistical analysis on 68 European sedan cars was carried out to characterize the 1974 vehicles. Some possible improvements were identified. A reference vehicle was selected and a fuel consumption prediction technique suitable for computer calculation was developed to evaluate fuel consumption and performance with and without incorporation of the possible improvements. Combinations of the individual improvements were chosen and applied to the reference vehicle; the corresponding fuel consumption gains were estimated. Within the constraints of the study 14 + 18% fuel consumption improvements were predicted for improved vehicles powered by improved gasoline engines or by high specific power gasoline engines. Only if poorer performance was accepted a 23 + 27% fuel consumption gain could be achieved by improved vehicles powered by a direct injection Stratified Charge Engine.