An on-board diesel particulate measurement (OBS-TRPM) instrument is developed to measure on-road exhaust PM emission at Horiba. It is used to characterize particulate matter (PM) emission from a gasoline vehicle, the 1999 Ford Windstar with California Ultra Low Emission (ULEV) certification. PM emissions from three test cycles, EPA FTP 72, SFTP-US06, and new European drive cycle (NEDC), are evaluated.
It is found that the PM emission from the SFTP-US06 with the cold start is roughly two times higher than PM emissions from the cold FTP 72 and the cold NEDC. This may be due to aggressive drive patterns for the US06 while the vehicle is still cold. The aggressive drive pattern for the US06 makes the gasoline vehicle emit a much higher fraction of elemental carbon (EC), and lower fraction of organic carbon (OC). Fractions of the EC from the vehicle are 9.1% for the FTP 72, 6.3% for the NEDC, and 56.6% for the US06.
Large fractions of the PM are found to be emitted at the engine start and during the first 200 seconds after the engine start, from all three tests. After the vehicle is fully warmed up, the PM emission from the US06 with the hot start is reduced by factors 7. In other words, it is likely to reduce the real-world PM emission from a gasoline vehicle significantly by avoiding the aggressive driving behavior while the engine and the aftertreatment for the emission control of the vehicle are still cold.