Emission factors of PM2.5 (g/km) are shown for heavy-duty diesel trucks and light-duty diesel vehicles. Data labels indicate the percentage reduction in emissions from the previous standard, with the series on the right depicting the total percentage reduction from conventional (uncontrolled) to Euro 6/VI. Selective catalytic reduction (SCR) systems control NOx (not shown) and allow engine tuning to reduce PM2.5 emissions for heavy-duty diesel vehicles meeting Euro IV standards and light-duty diesel vehicles meeting Euro 6 standards. Diesel particulate filters (DPFs) are employed to meet Euro 5 standards for light-duty diesels and Euro VI for heavy-duty vehicles.
Source: The impact of vehicle and fuel standards on premature mortality and emissions