SUMMARY
Paper provides the summarized results of high-speed and direct-injection compression ignition engines (further diesel engines) VALMET 320 DMG (ship gen-set) and Audi 1Z (passenger vehicle) performance research, which was carried out using different kinds and types of biofuel. Main attention focused on energy and environmental characteristics of diesel engine performance using 1st, 2nd and 3rd generation alcohol, fatty acid methyl and butyl esters blends with conventional diesel fuel (EN 590). Results of biofuel blends use instead diesel fuel showed that the efficiency of energy use increases 1–4%; at practically unchanged NOX concentration unburned product (CO, CH) concentration decreases up to 20% and exhaust gas smokiness – 55–85%.