The Effects of the Catalytic Converter and Fuel Sulfur Level on Motor Vehicle Particulate Matter Emissions:  Light Duty Diesel Vehicles

Wind tunnel measurements and direct tailpipe particulate matter (PM) sampling are utilized to examine how the combination of oxidation catalyst and fuel sulfur content affects the nature and quantity of PM emissions from the exhaust of a light duty diesel truck. When low sulfur fuel (4 ppm) is used, or when high sulfur (350 ppm) fuel is employed without an active catalyst present, a single log-normal distribution of exhaust particles is observed with a number mean diameter in the range of 70−83 nm. In the absence of the oxidation catalyst, the high sulfur level has at most a modest effect on particle emissions (