The paper discusses the possibilities of a synthetic assessment of a harmful impact of combustion engine emissions on humans and their natural environment. The ways of air quality evaluations have been analyzed. The authors analyzed the relations of emission charges for combustion engines as per the proposal of the directive of the European Parliament and the European Council in line with the Announcement of the Minister of Environment. A synthetic assessment of the emissions from combustion engines has been proposed. The method of emission assessment was used for the research on the ecological properties of a classic EURO IV diesel engine and a diesel engine fuelled with E95 bioethanol fuel.