Real Driving Emissions of Euro 6 electric/gasoline hybrid and natural gas vehicles

Electric hybrid powertrain and natural gas fuel for spark-ignition engines are among the much promising technologies to reduce the fossil fuel use for road transportation and the emissions of harmful and greenhouse gases. This paper investigated gas and particulate real emissions of hybrid and natural gas passenger cars. On road testing were carried out along urban, rural and motorway routes in Napoli (Italy), by using portable emissions measurement systems. Hybrid vehicle has the main advantage of fuel saving in urban environment due to large use of pure electric mode operation at low speed and load. On the other hand, continuous engine restarting causes peak emissions due to a longer light-off time of aftertreatment systems. By analysing the Vehicle Specific Power, it was observed that at same positive values of power, natural gas vehicle is characterized by lower emission and fuel/energy consumption rates compared to the hybrid vehicle.