摘要:This paper focuses on the observation of a decrease in smoke opacity values in application of tested substance in selected vehicles with a compression ignition engine. The aim of the paper is to evaluate the ability of the tested substance to decrease the smoke opacity value in vehicles equipped with the compression ignition engine with mileage above 30,000 km. Measurements were carried out on the basis of determined measurement methods. From the results obtained in measurements on two vehicles, it can be concluded that the utilization of the tested substance led to a decrease in the smoke opacity value in both observed vehicles. The results of the experiment show further possibility for decreasing of emission production in exhaust gases of motor vehicles equipped with the compression ignition engine.