Characterizing emissions and optical properties of particulate matter from PFI and GDI light-duty gasoline vehicles.

Aerosol extinction coefficient ( β ext ) and black carbon (BC) were measured from three light-duty gasoline vehicles (LDGV), including two gasoline direct injection (spray-guided and wall-guided GDI, SG-GDI and WG-GDI, respectively) and a conventional port-fuel injection vehicle (PFI), over the Federal Test Procedure (FTP) and Supplemental FTP (US06) test cycles. Emission factors (EF) of BC and β ext in addition to aerosol single scattering albedo (SSA) were determined for different phases or segments of the drive cycles. WG-GDI showed the highest EF BC (13 mg BC/kg fuel and 2.5 mg BC/kg fuel) and EF ext (0.1 m 2 /kg fuel and 0.018 m 2 /kg fuel) during both FTP and US06 cycles, respectively. EF BC and EF ext for the GDI vehicles during cold-start (P1) of the FTP cycle were 7–60 times higher than the PFI vehicle. EF BC and EF ext from GDI (PFI) vehicles were lower (higher) on the more aggressive US06 cycle compared to the FTP cycle. During the FTP cycle, a significantly lower SSA was observed for WG-GDI (0.2) while higher SSA values were observed for all vehicles during the US06 cycle (0.28–0.49). [ABSTRACT FROM AUTHOR]