A procedure for calculating octane numbers of commercial gasolines with due regard for the intensity of interaction between molecules of blend components, and the mechanism of interaction of interaction of anti-knock additives with hydrocarbons is elaborated. Based on the models developed, a computer program is created for optimization of the process producing high-octane gasoline. The program allows quick and precise determination of the optimum ratio of components, which ensures production of commercial gasolines that meet all the requirements of regulatory documents.