Abstract: A hydrocarbon fuel additive being a solution of the active complex in an organic solvent is provided, wherein the active complex consists of: chiral ester C4-C9 and monocarboxylic acid C1-C6. The achievable technical result is the decrease in the hydrocarbon fuel consumption in gasoline and diesel internal combustion engines, boiler units from 4.7 to 9.9%, and, accordingly, the increase in the efficiency of these devices, as well as the extension of the range of tools to reduce the hydrocarbon fuel consumption and improve the efficiency of internal combustion engines and boiler units.