Assessment of particle and gaseous emissions and reductions from gasoline direct injection passenger car and light-duty truck during passive regeneration.

This study evaluated the effectiveness of two passive regenerating gasoline particulate filters (GPFs) on reducing both gaseous and particle phase pollutants from a gasoline direct inject (GDI) passenger car (PC) and light-duty truck (LDT). In the absence of filter regeneration, observations from this study are consistent with other studies demonstrating how particle number (PN), particulate matter (PM), and black carbon (BC) emissions were reduced from the two vehicles with the use of GPFs. The significance of this study was to demonstrate the ability of the GPF to mitigate gaseous and particulate pollutants during severe passive filter regeneration, which was often observed on the LDT during aggressive US06 drive cycle testing. Partial filter regeneration happened on the LDT during some FTP-75 tests, as well as on the PC during some US06 drive cycles, however, this did not impact the GPF filtration efficiency (FE) to reduce particulate and gaseous pollutants. Using a cleaner fuel with lower overall tailpipe PM emissions could potentially lead to more frequent partial regenerations. This could produce the benefit of lower exhaust back pressure during and immediately after regeneration but still provide sufficient reduction in both particle and gaseous emissions.