Alkaline transesterification of sunflower oil by n-butanol and ethanol on alkoxide-containing dried solutions of potassium hydroxide has been carried out. Complex character of spontaneous dividing of butanolysis products, accompanying with formation of three different species of glycerol layers, was observed. One of the later was found to be high-alkaline pure glycerol. Bench motor testing of biodiesel/diesel blends demonstrated slightly better power performance of butyl esters comparing with ethyl esters and regular decrease of harmful emissions (CO2, CO, NOx, CH) while increasing biodiesel fraction in mixture.