A Demonstration of the Emission Behaviour of 50 cm ³ Mopeds in Europe Including Unregulated Components and Particulate Matter 2011-32-0572

The European emission legislation for two-wheeler vehicles driven by engines of ≤ 50 cm₃ is continuously developing. One of the most important issues in the near future will be the finalization of the European Commission's proposals for future steps in the emissions regulations as well as the verification of the impacts of current standards on the market. To have a basis for the discussion about these topics, the Association for Emissions Control by Catalyst (AECC) with the Institute for Internal Combustion Engines and Thermodynamics of Graz University of Technology (IVT) carried out an extensive test program to show the actual emission situation of state-of-the-art mopeds including mass and number of particulate matter as well as unregulated gaseous components.

One of the main goals of these tests was to measure exhaust emissions without any modifications to the engines of standard production vehicles available on the European market. The selection of test vehicles was carried out to get the best possible variety of technologies representing the actual situation on the street. To gain a significant overview of the emission situation as well as the potential of different technologies, it was very important to take vehicles from both the two-stroke and the four-stroke segment. Within these main segments the range of vehicles should provide low cost technologies as well as high end solutions for engine control and exhaust gas aftertreatment. Beside the current and proposed future UNECE R47 measurement procedures, the chosen two-wheelers were also operated on the reduced speed WMTC part 1 cycle (this being the closest match available for moped specifications) to evaluate the influence of different testing procedures. Regarding the current regulations in the automotive sector as a possible future prospect for upcoming two-wheeler legislation, the emissions of particulate matter were also considered using a gravimetric measurement method as well as a particle counter to provide information about the mass of particulate and number of particles. Additionally, an FTIR measurement was included to provide information about the composition of the gaseous fraction of the exhaust gas. In respect of the proposed EURO 3 legislation the bag sampling was divided in two parts for all test cycles, being able to weight the results with different factors. Beside this overall measurement, the online recorded data of air/fuel ratio, exhaust gas temperatures and the development of emissions over cycle time delivers detailed information. Finally, the emitted particulate matter was analyzed with a Thermo Gravimetric Analyzer (TGA) to identify the mass fraction of organic carbon. The results of the conducted tests show a wide range of different emission results depending on engine technologies and testing conditions and can serve as a good basis for the consideration of the current situation on the street and the examination of proposals for further emission regulations.