Vehicle emissions in relation to fuel composition

In recent years there has been growing concern over the impact of non-regulated pollutants produced by vehicles and in particular the role of specific volatile organic compounds (VOCs). As yet there is limited information on the effect of changing fuel compositions on VOC emissions from gasoline fuelled vehicles. The basis of this study was, therefore, to investigate the relationship between emissions and fuel quality and consider its implications with respect to both indoor and outdoor air quality. Dynamometer studies were conducted using a standard test cycle and the total exhaust emissions over the complete cycle were sampled for subsequent analysis. Tests were performed on a variety of gasolines with differing amounts of olefin and aromatic compounds and the concentrations of specific VOCs were measured together with other pollutants of concern. Results of these studies were considered in relation to the changes in VOC emissions that could be released into street air as a result of using the fuels tested. In addition, in highly urbanised countries where dwellings and work places are in close proximity to vehicle traffic, changes in outdoor air quality will also be reflected in indoor air.