SUMMARYAn important cornerstone of our society is the individual mobility which, today, chiefly can only be offered by the automobile. However, in the industrial countries the car at the same time is exposed to harsh criticism as far as environmental pollution is discussed.Goal of this presentation is to show a scientific method by means of which environmental loads during manufacture, use and utilization/disposal of whole systems - in this special case vehicles - can be quantified and optimized. In order to do this, the instrument of life cycle analysis of parts and processes is used and in the same way the scientific method is developed beyond the level of literature. Due to these modifications the results are only useful if the boundary conditions are mentioned in detail.Considerations on the system such as the examination of an automobile require a method extended by essential criteria due to its complexity. Possibilities are presented which help to describe the product life cycle of an automobile, sufficiently accurate by careful examination of the main parameters such as material, material intensity and fabrication procedures.As demonstrated on a small car, an automobile of upper standard and a train respective ways of action are shown and results of a system analysis are represented. As regards automobiles various weak points exist. On the one hand these are specific parameters during manufacture and on the other hand during the utilization phase the fuel consumption and its production. The track-bound traffic shows disadvantages if the generation of current is unfavorable. Therefore optimization potentials are to be seen in the field of fuel efficiency and its underlying factors as well as in the field of electricity supply.