PEMS-Based Comparative Study on Real-Road Emissions from Hybrid Electric and Gasoline Vehicles

A series of real-time on-road emission testing is conducted on PRIUS, a HEV car, and Yuanjian, a conventional gasoline-fueled car using a portable emission measurement system (PEMS). The emission and fuel consumption characteristics of PRIUS and Yuanjian during idling, cruising, accelerating and decelerating modes, on congested versus non-congested roads, and on uphill versus downhill roads, are analyzed. The experiment results show that, throughout the urban testing cycle, the fuel consumption of PRIUS is 62.6% of that of Yuanjian, and all of the emission factors of PRIUS are two-thirds lower than those from Yuanjian. The emission contribution of PRIUS during idling is almost zero percent. The fuel consumption of PRIUS on congested and non-congested roads are 55.1% and 87.4% of those of Yuanjian, and all of the emission factors of PRIUS are three-fourths lower than those from Yuanjian on congested roads. The emission factors of Yuanjian on congested roads are almost 1.45–2.38 times of those on non-congested roads, while those of PRIUS do not show noticeable increase on congested roads over the non-congested roads. In fact, the emissions of NOx and HC of PRIUS on congested roads are even lower than those on non-congested roads.