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Tailpipe particulate emissions, i.e., particle number, size distribution and total mass, from a series of four cylinder engines with 2L displacement and power output of approximately 150 hp have been measured. The engines were in their respective vehicle installation, all midsize vehicles from various manufacturers, and represented different combustion concepts, i.e., port- and direct injected vehicles and E5 and E85 fuels. The results are compared to post Euro V emission standards for gasoline and biofuels using diesel as reference. The results show that the type of combustion and fuel significantly affect the particulate formation. In general, direct injected engines show high particle numbers and mass compared to port injected engines. The particulate number and total mass can be reduced by using biofuels, e.g., ethanol mixes, instead of gasoline.

Model NOx storage catalysts were used to study the sulphur deactivation of these systems using reactor studies, FTIR and XPS. It is found that the deactivation rate shows a linear dependence on the SO2 concentration and that bulk sulphates are easily formed. Experiments with SO2 present either during lean or during rich conditions show a more rapid deactivation in the latter case.