LAUSR

The aim of paper was to discuss contribution of bi-fuel CNG powered light commercial vehicles to the Well-To-Wheel CO2 equivalent emissions, both today and in the coming decades in which the development of new fuels and new vehicles is expected. Field research was done in Belgrade, during one year, using Euro 5 diesel/LPG/CNG light commercial vehicles driving under low vehicle speed, low engine load, low exhaust gas temperature and high number of stops. WTW as neutral methodology was applied for understanding of each fuel pathway in terms of reducing greenhouse gas emissions and increasing energy efficiency. Calculation showed that total energy consumption per km is the lowest for diesel vehicles since petrol/LPG and petrol/CNG vehicles use 21% and 7 % more energy. Tank-To-Wheel emission of CO2e is most favorable for petrol/CNG with 28.8 % and 6.7 % less CO2e with petrol/LPG and diesel vehicles. The same conclusion brings Well-To-Wheel analysis showing that diesel/CNG CO2e emission is 13.5 % less than petrol/LPG, apropos 1.5 % less than diesel operated vehicles considered within this field research. Figures are not as high as previous, due to the results of Well-To-Tank emission, that were most favorable for petrol/LPG powered vehicles, with almost 51% and 32% better results regarding to petrol/CNG and diesel, respectively. Within same time, lowest fuel cost per km was achieved by petrol/CNG vehicles, with 32% and 35% less cost than petrol/LPG and diesel vehicles. The available CNG technology should not be neglected, waiting for new solutions to be proven.