In all the world mopeds and motorcycles are popular means of
daily moving, helping to meet daily urban transport needs, as a
consequence two-wheelers contribution to air pollution is generally
significant, especially in urban environment. Emission models
commonly used in Europe, are based mainly on the average trip speed
to predict emissions, thus they are not sensitive to variations of
vehicles instantaneous speed and acceleration, which have a strong
effect on emissions and fuel consumption; besides these models do
not analyze in depth the cold emissive behavior of motorcycles. An
expansion of the two-wheelers emission database was deemed
necessary.
This study is aimed at the examination of the emissions of
in-use motorcycles during real driving conditions, contributing
significantly to extend the knowledge of two-wheeler emission
behavior. For this purpose, an experimental investigation was
realized by the Department of Mechanic and Energetic (DiME) of the
University of Naples: emissions of regulated pollutants (CO, HC and
NOX) were evaluated in the exhaust of one scooter belonging to
the Euro-3 legislative category, equipped with catalytic converter,
and with a displacement of 300 cm₃. In order to evaluate the
performance of this motorcycle under real-world motorcycle riding,
in cold and hot conditions, sampling was achieved on a dynamometer
bench during both the Type Approval driving cycle and real-world
driving cycles, also by employing the instantaneous emission
results. The experimental data and the statistical processing
results of this research are compared with current emission models
for calculating emissions from road traffic.