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This paper describes various aspects of the particle emissions from a 2-stroke motorbike. It gives an indication of issues which may face emissions engineers if (or when) such vehicles become subject to particulate legislation similar to that for light duty vehicles. A DMS500 fast particulate spectrometer was used to examine transient particle emissions from the CVS tunnel for two 2-stroke motorbikes over the European ECE R47 and urban New European Drive Cycle (NEDC) drive cycles. One was direct injected and the other was carburretted. Transient size spectra and number data from the output of a two stage, Particulate Measurement Program (PMP) compliant heated dilution system are presented for the carburretted 2-stroke motorbike running the urban phase of the NEDC. Estimates of the particle number emissions relative to the Euro 5b light-duty diesel vehicle legislation are presented.

The gaseous and particulate emissions from a diesel passenger car have been studied during cold start and Diesel Particulate Filter (DPF) regeneration events occurring during the New European Drive Cycle (NEDC). During the initial phase of the cycle, Diesel Oxidation Catalyst (DOC) light-off was seen to be highly dynamic with catalyst efficiency changing dramatically with changes in catalyst temperature. Accumulation mode particulate emissions were sampled directly from the exhaust after the DPF. From cold start with a clean (regenerated) DPF, accumulation mode particle emissions were seen to be very much higher than those from a loaded DPF. This accumulation mode slip lasted only approximately 200 seconds. During regeneration of the DPF, the oxidation of trapped soot was associated with a large tailpipe emission of nucleation mode particles.