An experimental study on the impact of biodiesel origin on the regulated and PAH emissions from a Euro 4 light-duty vehicle

► Emissions of NOx and CO2 were higher with biodiesel blends, while PM, CO, and HC emissions decreased with biodiesel blends. ► Higher NOx emissions obtained with increasing unsaturation of the biodiesel and PM reductions observed with the saturated blends. ► The biodiesel blends resulted in increases in light PAH emissions and in important reductions in larger PAHs. ► The oxidized biodiesel blends exhibited higher PAH emissions compared to the other blends and diesel fuel. ► The unsaturated biodiesel blends provided larger increases in PAH emission than the more saturated biodiesel blends.