The paper includes a brief description of the methodology of obtaining dynamic characteristics of four basic exhaust gas emissions: CO2, CO, HC and NOx based on combined data from road tests on the engine test beds NEDC and FTP-75. The characteristics developed through tests on a class C motor-car have been presented. The possible advantages thanks to the application of the dynamic characteristics developed have been indicated. The significant values of emission during engine braking have been pointed out. For a wider recognition of this area of dynamic characteristics, special chassis tests were carried out on the engine test bed, recording the emissions of the exhaust gas components listed in the modal system with 0.4 s rate in the test of full engine braking on III, IV and V gear. The results were summarized and assessed.