Assessing the real-world performance of modern pollutant abatement systems on motorcycles

The present statutory pollutant emission limits Euro-3 for motorcycles imply the use of modern emission abatement systems such as three-way catalytic converters. Determining the quality of implementation of these new systems in different driving situations such as real-world driving is important, since motorcycles are commonly used for personal transportation in urban areas. For this reason, a test bench series was carried out with a sample of 10 motorcycles of state-of-the-art certification category Euro-3. Emission factors of regulated pollutants and CO2 are presented on the basis of the statutory driving cycle, the latest version of the real-world Worldwide Motorcycle Test Cycle (WMTC) and the real-world Common Artemis Driving Cycle (CADC).The results of the statutory driving cycle show that 7 out of 10 motorcycles fail to comply with the present emission limits. The results of both real-world driving cycles confirm notable emissions of HC in urban and NOx in motorway driving conditions. CO emissions of motorcycles with small displacement increase significantly in the urban and extra-urban sections of the CADC, which has a more dynamic velocity profile than the equivalent WMTC. Although pollutant emissions of motorcycles show a marked improvement compared with earlier certification classes, they clearly exceed the emission levels of modern light gasoline passenger cars, especially for CO and HC.