“…Again in this case, RME does not show any considerable variations in number distribution, compared to diesel fuel, while an appreciable reduction can be observed in the mass size distribution, with a peak diameter at about 50 nm and 100 nm, respectively, for both fuels; conversely, at this engine operating condition, JME leads to a remarkable increase in PN, as well as in particle mass, with almost doubled peak distribution values compared to diesel fuel; while an appreciable reduction in number and mass can be also observed for particles below 10 nm. The large increase in particle number measured with JME could, at least in part, be attributed to a slight change in the EGR rate, which is likely to produce a dramatic change in soot emissions, due to the particular setting of the engine calibration point on the soot-NOx trade off which was highlighted in a previous research activity [7]. Therefore, the extremely important effects on PM emissions that can be attributed to shifts in the engine operating points on the calibration maps, highlight the need for a specific adjustment of the engine calibration on the basis of the fuel characteristics (e.g.…”