Abstract: A method of preparing a mixture consists in successive performing of: atomization of fuel in a stream of exhaust gases, introduction during suction or an exchange of the load an incombustible fuel-combustion mixture to a separate storage space, compression--in a positive-displacement manner without mixing--of the mixture with the air inflowing to the storage space from the working space of the engine, forcing through of the compressed mixture into the combustion chamber before the top dead center of the piston completing the compression stroke, and in production of a combustible mixture by mixing with air compressed in the combustion chamber.