Toxicological properties of diesel engines’ exhaust gases, in particular polycyclic aromatic hydrocarbons, as well as diesel engines’ exhaust gases composition, toxicity assessment technique for exhaust gases of diesel engines working at different types of fuel have been presented. Advantages related to use in diesels a biological fuel made on basis of vegetable oils have been shown.

The article displays advantages of using multicomponent mixed biofuels for diesel engines, i.e. mixtures of oil diesel fuel and rapeseed oil, rapeseed oil methyl ester, gasoline. The results of experimental research on a D-245.12C type automotive diesel engine running on these fuels are presented. A method of determining the optimal composition of multicomponent biofuels is proposed. Using this method optimization calculations of the fuel compositions are made. It is demonstrated that among tested biofuels the mixture of 80% oil diesel fuel, 10% of rapeseed oil and 10% of gasoline possesses the superior ecological parameters.