An approach towards comprehensive Life Cycle Assessment (LCA) for surface transport automotive fuels

Life Cycle Assessment (LCA) of a fuel is commonly known as ‘Well to Wheel’ (WTW) analysis, which is divided into two stages, viz. the ‘Well to Tank’ (WTT) or fuel stage, and the ‘Tank to Wheel’ (TTW) or vehicle stage. In both these stages, the physico-chemical of the fuel as well as and the technical attributes of the vehicle are taken into the consideration to assess the environmental impacts of an automotive fuel. There are also several factors that are exclusive of the internal fuel characteristics and the vehicle propulsion system that influence the emissions. These factors can be either natural or environmental (e.g., local topography, wind parameters, and average ambient temperature etc.) or man-made (health of the road network, traffic density and traffic management system, and customer attitude etc.). These factors along with the vehicle design-based attributes impact the rolling resistance, the aerodynamic drag resistance, and the inertial resistance. The power supplied to the wheels need to be manifested into the distance covered by a wheel depending upon these independent external factors. Therefore, the WTW approach has been extended to have the complete LCA of a fuel and this extension is named as ‘Wheel to Miles’ (WHTM). In the TTW part, the quantity of the fuel consumed is assessed, whereas, in the WHTM part, the quality of the consumed fuel is analyzed in terms of the mileage realized. All the three major resistances (rolling, air drag and inertial) are impacted by the natural, man-made and vehicle design based factors and in turn, they impact the vehicle fuel economy. A change in rolling resistance has high impact on the fuel economy among all the three resistances analyzed. The fuel economy of a freight vehicle is majorly impacted by a change in the coefficient of rolling resistance, while that of a passenger vehicle is more sensitive towards a change in the drag coefficient