A driver’s aid displayed speed trace of the driving cycle to follow with a tolerance of ±1 km/h. A variable speed blower, positioned in front of the two-wheeler vehicle, acted as the cooling wind on the road. During the tests, the exhaust gases were diluted with purified ambient air by a Constant Volume Sampling with Critical Flow Venturi (AVL CFV-CVS) unit. The diluted exhaust gas was passed throughout a dilution tunnel for reaching stable flow conditions. A part of diluted exhaust was sampled downstream the dilution tunnel for continuously measuring the concentration of CO, HC, nitrogen oxides (NOx) and carbon dioxide (CO2) by an exhaust gas analysis system (AVL AMA 4000). The signals were corrected for the time delay respect to the speed; no other compensation (i.e., mixing dynamics) or signal treatment was applied (Ajtay et al. 2005). Simultaneously, the average values of regulated pollutants were measured in a sample bag filled during the test.