There were studied the influence of composition of foreign marine fuels on its quality indexes which estimate the combustibility and combustion efficiency of this fuels in the marine reciprocators. It was found that using the high-density fuels in the engines of marine technique, which specified for exploitation on the automotive diesel fuels, can be the cause of decreasing the combustion efficiency, increasing of smokiness of exhaust gases and facility of technique’s failure. Using of methyl esters of fatty acids in the marine fuel’s composition in concentrations until 1 mass percent influents positively on combustibility and combustion efficiency. This result in the aggregate of results of other researches of influence these concentrations of FAME on the emulsification and lubricity of marine fuels follows to possibility of its short-time using marine technique. Experimentally proved the necessity of offered calculating method which estimates the combustion efficiency and combustibility of marine fuels. It was found that this method is more adequate and sensitive for estimation of those properties of heavy marine diesel fuels and petroleum diesel fuels with the FAME contention then the method of estimation of Cetane Index (GOST 27768).