The main utilitarian goal of the research project carried out was to develop a methodology for testing a new type of marine fuels in the actual operating conditions of a ship engine and for ranking their energy and emission quality. It is expected to significantly complement the ISO 8178 standard "Reciprocating Internal Combustion Engines - Exhaust Emission Measurements. Part 10: Cycles and test procedures of operational smoke opacity measurements of compression ignition engines operating in transient conditions ”. In order to achieve the assumed research goal of the project, it was necessary to solve the following specific issues: • Design and construction of an external installation for a laboratory engine for preparation of marine fuel (heavy residual fuels) for combustion. It includes the possibility of cleaning and heating it in terms of maintaining the required viscosity before feeding it to the combustion chamber; • Modernization of the engine fuel supply system consisting in the use of a gradual transition system between fuels with large viscosity differences (mixing distillation fuel with residual fuel); • Design and construction of a stationary measurement system enabling the observation of engine control parameters and parameters of the working process, as well as the concentration of selected chemical components in the exhaust gas and thermal and flow parameters in the exhaust gas system; • Modification of the stand for testing the injection and atomization process of fuel into the "cold combustion chamber"; • Development of a test program and performance of engine tests with the use of representative marine fuels; • Development of a method for determining the static and dynamic characteristics of the engine; • Development of algorithms for determining diagnostic parameters characterizing the energy and emission quality of marine fuels; • Development of a standardization method for the determined diagnostic parameters for the preparation of a ranking of the quality of tested marine fuels; • Assessment of the technical condition of the engine after completion of each engine test with the use of a new type of marine fuel. A single-cylinder, four-stroke, compression-ignition Farymann Diesel type D10 engine was used to carry out the tests, driving a DC generator through a belt transmission. The generator, in turn, powers the residual ("heavy") marine fuel heating system. In order to obtain comparable test conditions, each engine tes