This paper presents a chemmotological process modeling method which, based on the results of fuels and lubricants (FL) tests on physical models of FL using objects, enables computer construction of mathematical and simulation models of the processes and use of them for evaluating and predicting the performance properties of FL's with due regard for the probability characteristics (distribution laws) of the FL composition and the actual modes and conditions of operation of the equipment. The results of approbation of the method, as applied to motor fuel properties, are presented.