DfT Motorcycle Emissions Measurement Programmes: Unregulated Emissions Results

As part of a UK Government programme to determine emissions factors for a variety of vehicles, further study was undertaken to measure individual chemical species of current and possible future concern. The aim of the study reported here was to investigate the unregulated emissions from a range of twelve 2- and 4-stroke motorcycles with respect to various drive cycles, engine and aftertreatment technologies.

Data were generated using specialised Fourier Transform Infra-red Spectroscopy (FTIR), On-line Mass Spectrometry (OLMS) and Condensation Particle Counter (CPC) instrumentation for the real-time determination of individual inorganic, hydrocarbon and particle number concentration data. Analyses of particulate mass, mass weighted particle size distribution and further chemical composition analyses including particle and vapour phase polycyclic aromatic hydrocarbons (PAHs) were also conducted.

Testing was conducted over three drive cycles described by the following directives:

• 97/24/EC (Chapter 5, Annex 2)
• 98/69/EC (Motorcar cycle)
• WMTC version 7 (developmental cycle)

Comparative emissions results are presented between motorcycles and between the various drive cycles.