The article studies the best effect of organic oxygen-containing esters on the octane number of petroleum fuels obtained as pre-medicines and analyzes their physical and mechanical properties. The impact of the proposed additives that help to raise the octane numbers E-1, E-2, and E-3 on the octane number of fuel was studied in two ways: research and motor. Preliminary findings show that the proposed additives have a positive effect on the octane number compared to analogues. Based on the results of experimental tests, it was proven that the additives can be used to raise the octane number of fuels. When introducing additives based on organic esters E-1, E-2, and E-3 into reformed gasoline, their efficiency in terms of octane number was determined to be 0.1–1.1 units higher than that of analogues by research and motor methods.