Effect of Lube Oil on the Physicochemical Characteristics of Particulate Matter Emitted from a Euro 4 Light Duty Diesel Vehicle

This paper investigates the effect of lubrication oil on the physical and chemical characteristics of the particulate matter (PM) emitted from a Euro 4 diesel vehicle. Two different lubrication oils were examined. A fully synthetic ACEA grade B3 service-fill oil of low sulfur content (1760 ppm wt.) falling into the OW-40 SAE viscosity grade and a mineral ACEA B2-98 motor oil of high sulfur (8890 ppm wt.), falling into the 15W-40 SAE viscosity grade. To exclude interferences from the fuel derived sulfur, a rather sulfur-free fuel (< 10 ppm wt.) was used in the experiments. The experiments included steady state tests, the certification cycle and real-world highspeed transient driving conditions. The properties measured included total particle mass collected on Teflon-coated filters, total particle number measured by a condensation particle counter, size distributions determined by a scanning mobility particle sizer. Chemical analysis was performed to investigate the metallic and the ionic character of the particulate matter for the different lubes. Results showed that the vehicle complies with the Euro 4 emission limits when tested over the type-approval NEDC regardless of the lubrication oil used. Both PM mass and number were drastically reduced with particle filter.