To expand the raw materials base for the production of biodiesel fuel, it is advantageous to make use of biobutanol (B) produced from renewable resources, which can be used in two ways as fuel for diesel engines: by direct inclusion into multicomponent fuel for diesel engines or by producing fatty acid butyl esters from rapeseed oil. Multicomponent fuels D70/B30, D70/B15/RME(RBE)15, and D50/B25/RME(RBE)25 meet the standards for fossil diesel fuel (D) and biodiesel fuel in terms of the main indicators of quality. When 30% biocomponents are included in a mixture with fossil diesel fuel, the effective efficiency factor of the engine (ηe) is as high as that of pure fossil diesel fuel, and reductions are achieved in the emission of all harmful components (CO, HC, NOx, and BSN). Usage of a such mixture is more promising if compared with a mixture containing higher content of biocomponents. Increase of biocomponents to 50% causes an increase in ηe of up to 4% compared to that of fossil diesel fuel, reduction in ...