Determining the control of the petrol engine of a car which is to meet the requirements of the EUROTEST (UDC+EUDC, Reg. ECE 83) test needs the identification of the engine load trajectory, which is dependent on the speed trajectory, gear change and other test parameters. The solution to the problem leads to generating so-called "characteristic points" of motor operation with the known density of appearance in the test. In the present publication, the authors have made no attempt to answer the question how the number of characteristic points influences the result, i.e., the emission of toxic compounds and the fuel consumption. The evaluation will be carried out basing on the petrol engine model, which was constructed as a result of developing the empirical model described in publication in the EUROTEST conditions.