Aging factor
Emissions factor of aged vehicle
Emissions factor of new vehicle
ð7Þ
In order to reduce the scatter of data, 125 cc engine displacement volume motorcycles were grouped into three age
groups: less than two years old, between two and five years old, and more than five years old. Aging factors were calculated
based on the mean emission factors of each group. In Fig. 9 different pollutant aging factors are presented. Using regression