The effect of start-stop systems on scooter exhaust emissions

Abstract The paper describes the analyses of the exhaust emissions from a city scooter performed under actual operating conditions. The measurements of the exhaust emissions were performed for CO2/fuel consumption, CO, HC and NOx. The investigations were carried out in actual traffic of high congestion in Poznan (Poland) in a driving cycle of the length of 7.35 km. The analyses were performed on a scooter fitted with a 125 cc engine with a start-stop system. The performed analyses revealed that the actual emissions of CO and HC were greater by 57% and 4%, respectively for the scooter with the start-stop system enabled, while the emission of NOx decreased by 10%. The application of the start-stop system contributed to the reduction of the fuel consumption/CO2 emission by approx. 12%. Large differences between the emission in real operating conditions and the Euro 4 emission standards have been obtained.