Because of the main use in urban environments, experimental determination of emissions from these vehicles is then very important for estimating their contribution to total emissions attributable to road transport and then for studying the most realistic ways of making progresses to ground-level air quality (European Commission2013). Comparison and appraisal of emissions produced by two-wheelers and passenger cars disclose that the absolute emission level of passenger cars has been reduced noticeably in the last two decades, due to the introduction of legislation together with tightening the applicable limits on regulated emissions for these vehicles, while, on the other hand,