Gaseous and Particulate Emissions of a Euro 4 Motorcycle and Effect of Driving Style and Open or Closed Sampling Configuration

Abstract

Air pollution remains a serious concern for European citizens. The relative contribution of mopeds and motorcycles to air pollution started to increase as the levels from other vehicles started to decrease. The information on emission levels of Euro 4 motorcycles is limited because they were only recently introduced into the market (2016). In this study, the emissions of a 1 L Euro 4 motorcycle were determined with two drivers and two different sampling configurations (i.e., open or closed transfer tube to the dilution tunnel; both allowed in the current regulation). The motorcycle respected the current Euro 4 limits and even the future Euro 5 limits for most pollutants (CO 600 mg/km, NOx 48 mg/km, total hydrocarbons 60 mg/km). The particulate emissions, which are not regulated for this category of vehicles, were also very low and fulfilled the current limits of passenger cars (particulate mass < 0.5 mg/km, particle number 3 × 1011 p/km). The total particle emissions (i.e., including volatiles) were also low with the open configuration (6 × 1011 p/km). They increased more than one order of magnitude with the closed configuration due to desorption of deposited material from the transfer tube. For the gaseous pollutants, there was no significant difference between open or closed configuration (CO2 within 0.3%, rest pollutants 10%), but they were different between the two drivers (CO2 1.3%, rest pollutants 25%–50%). The main message from this work is that open and closed configurations are equivalent for gaseous pollutants but the open should be used when particles are measured.