The paper provides the results of an integrated research of the energy, environmental performance and traction indicators and the characteristics of fuel feed and performance of A41, 2F511, VALMET 320 DMG and �: udi 1Z highspeed, direct-injection diesel engines when converting their operation from mineral diesel D to the fatty acid esters (RRM �? and RRBE) and alcohol biodiesel mixtures. The researches are carried out in cooperation of the Lithuanian and Polish partners within the framework of joint scientific projects under EUREKA international scientific program “E!4018 CAMELINA-BIOFUEL”. In the light of the new EU initiatives (“White Paper” 2011), 30% optimum part of RRME bio-component in the mixture with D (B30) is validated for practical use. The characteristics of fuel supply and heat generation in a diesel cylinder are under investigation; an explanation of a significant reduction in the harmful component emission (EG) and 2 to 4% increase in the fuel efficiency in case of use of B30 and B10 biodiesels is offered. The presence of the ethanol alcohol component ( �? ) in D-RME-E and RME-E biofuel mixtures resulted in reduction of CO and NOx emission by 10 to 12% and EG smokiness – by 20% per each 10% increase of E part. The indicated efficiency of performance was increased by 2-2.5%. The indicators of cyclic instability did not exceed the corresponding indicators in diesel operation on D. It is established that the motor properties of tested B30 and B50 biofuels based on butanol and rapeseed oil butyl ester RBE are similar to RME biodiesels and have important advantages over them: the