Emissions and fuel consumption of a Euro 4 car operating along different routes in Hong Kong

This paper analyzes the on-road emissions and fuel consumption of a Euro 4 petrol car driven on four typical urban routes in Hong Kong. The effects of road grade and traffic condition on the emissions and fuel consumption are examine and show that the hilly route has the greatest CO and HC emissions and the highest fuel consumption per unit distance traveled. The urban route is the second highest in CO emission and fuel consumption due to significant idling and low-speed operation, and the frequent acceleration and deceleration changes. It is also found that higher NO.xemission is associated with deceleration events which cause lean operation while higher CO emission is associated with accelerating from idle which causes rich operation. HC and fuel consumption peaks are associated with acceleration.