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

Aerosol extinction coefficient (beta(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 beta(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 EFBC (13 mg BC/kg fuel and 2.5 mg BC/kg fuel) and EFext (0.1 m(2)/kg fuel and 0.018 m(2)/kg fuel) during both FTP and U506 cycles, respectively. EFBC and EFext for the GDI vehicles during cold-start (P1) of the FTP cycle were 7-60 times higher than the PFI vehicle. EFBC and EFext from GDI (PFI) vehicles were lower (higher) on the more aggressive U506 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 U506 cycle (0.28-0.49). (C) 2015 Elsevier Ltd. All rights reserved.