Comparison of number, surface area and volume distributions of particles emitted from a multipoint port fuel injection car and a gasoline direct injection car

A chassis dynamometer study was conducted to compare the characteristics of particle emissions from a port fuel injection (PFI) and a gasoline direct injection (GDI) car, both of which comply with Euro 4 exhaust emission standards. Experiments were carried out over the New European Driving Cycle (NEDC), the ECE-15 segments, the period from 0 to 49 s within the NEDC procedure (FSE) and the Extra Urban Driving Cycle segment. Exhaust particles were characterized in terms of the particle number, surface area, volume and size distributions between 30 nm and 1 mu m. Under the NEDC, the GDI car had particle emissions weighted by particle number, surface area and volume that were 56-2 739% higher than the emissions from the PFI car in the range of particle size measured, and the particle number, volume and surface area emissions per km for the GDI car are respectively 5.3, 9.0 and 14.6 times higher than those for the PFI car. Among the testing conditions employed, the highest concentrations of average particle number, surface area and volume were found in the FSE, and the particle number, surface area and volume for the GDI car were respectively 9.5, 33.2 and 39.8 times higher than those for the PFI car. Moreover, the peak of the particle size distributions for the PFI car was toward a smaller size, while that for the GDI was toward a larger size, indicating that particles emitted by the PFI car are much smaller than those emitted by the GDI car.