Transient PM emissions from 3 GDI and 1 PFI vehicles under the NEDC cycles were reported.

The primary aggregate size distribution obtained from TEM image analysis was in consistent with the size distribution measured by the DMS500.

Acceleration has great impact on the PM emissions under warm conditions, whilst the torque has a significant impact on the PFI vehicle PM emissions under cold conditions.

TWC effect on nucleation particles was investigated under varying motor power and engine speed.