Fig. 2

Overall VOC emissions of gasoline and PHEV vehicles on WLTC at 23 °C as a function of the starting condition. COLD refers to a test where the ATS temperature at the starting point is the same as the climatic cell temperature (23 °C ± 3 °C) and are the same emission results of those reported in Fig. 1, included to ease the comparison. HOT refers to a test carried out immediately after another test so that the after-treatment system is already warmed up