Reducing air pollution caused by automobiles and energy conservations

Efforts made by industralized countries to reduce air pollution give consideration to the need for energy conservation made necessary by the economic situation. The compatibility of these two objectives with regard to automobiles is examined. All antiwaste or antipollution efforts not involving the energy generator make up an obvious area of compatibility. On the other hand, the reduction of pollutant emissions requires more or less far-reaching changes in engines, including some that may create problems from the standpoint of energy conservation. In an attempt to specify the nature of such problems, pollution-control techniques corresponding to different levels of emission limiting are examined from the standpoint of their cost, their influence on fuel consumption and their interaction with energy-conservation processes. A review is made of emission-reduction methods based on improving combustion, post-combustion processes, and the problem of reducing the lead content of gasonline. This analysis shows that, to a large extent, the reduction of pollutant emissions and the decreasing of consumption are compatible objectives, but that the complexity of the problems that have to be solved so that pollution-control measures do not have a negative effect from the energy-conservation standpoint increases very rapidly with the severity of these measures beyond a certain level.