The EU and Lithuania have developed and subsidised the production of first generation biofuels (bioethanol, biodiesel (RME)) produced from food-friendly raw materials, but due to low economic and ecological efficiency, this support is planned to be discontinued due to energy and environmental problems. The production of second and third generation biofuels (waste and non-food feedstocks) will be supported, with a life-cycle reduction of 60 % of CO2 emissions. Optimisation of performance factors for compression ignition engines operating in blends of first and second generation biodiesel and diesel would improve the efficiency of alternative fuels and reduce environmental pollution. The aim of the project is to experimentally study the performance of compression ignition engines operating in the first and second generation blends of biodiesel and diesel and to optimise the factors influencing them. The student will acquire knowledge and practical experience in the field of performance research of compression ignition engines operating on first and second generation biodiesel and diesel blends. The student will master the research methodology, familiarise himself with the principles of analysis of the results obtained, examining the energy and ecological indicators of internal combustion engines, and evaluate the positive aspects of the use of alternative biofuels. The results of the scientific and practical research will follow the trends of vehicle development: the use of alternative fuels, improving energy efficiency and reducing environmental pollution. Theoretical and practical experience will be gathered for further research into internal combustion engines of II and other generations of biofuels.