Measurements on the exhaust gases from the eight vehicles of Euro 5 diesel buses and NGVs of each manufacturer were carried out to ensure reliability.
According to the study, when compared the average value of pollution emission per kilometer at NIER-06 mode, the most similar mode to the average running speed (19.8km/h) of intra-city buses of Seoul, CNG buses had better environmental performance than diesel buses for CO, NOx, PM, CO2 and particle number.
NOx of diesel bus was 10.28g/km, 2.8 times the value of CNG bus, 3.62g/km, VOC was 5.33mg/km and 3.68mg/km each and CO was 1.82g/km and 0.06g/km.
From the assessment on economic performance based on the results of the study, it was found that policy of disseminating CNG buses is feasible as economic performance of 73 million won (approximately USD 68,000) per vehicle is expected.
Source: Ministry of Environment, Republic of Korea.
