Diesel engines are mostly used for diesel engines and even for Dual Fuel DF engines, but there is a growing tendency to use gas as a propellant. Liquid fuels for ships are fossil or originating, while gas fuels can be natural (natural gas) or the result of distillation of fossil fuels. Marino Diesel Fuel is a mixture of several different hydrocarbons, starting from a compound containing from 9 to 23 carbon atoms in the molecule. The primary goal of all fuels is to convert energy from combustion to useful mechanical engineering with the least loss of heat, with the highest usability. Fuel quality is conditioned by the number of hydrocarbons, and the hydrocarbon ratio among them is determined by the type of oil from which it is obtained. In recent decades, the shipping industry and maritime traffic have grown rapidly. There are currently more than 50 000 merchant ships operating in international waters and account for about 90 % of the world's trade. Today, attention is paid to the protection of the atmosphere from the emission of harmful exhaust gases. Combustion of fossil fuels in the atmosphere emits carbon dioxide, sulfur dioxide and nitrogen oxides that contribute significantly to environmental pollution.