Evaluation of Variability in On-road Vehicle Fuel Consumption under Controlled Conditions

The fuel consumption is an important component of the vehicle operating cost which is a significant component of the total transportation cost. Fuel consumption data are extensively used by transport planners, transport managers and other professional for various evaluation processes in overall gambit of sustainable transportation system. Accuracy of fuel consumption data is one of the key factors in deriving realistic vehicle operating cost component. Minimizing uncertainties in fuel consumption measurements enhance the quality of data. In an attempt to understand the variability in observed fuel consumption under controlled conditions, field studies were carried out using a petrol-driven control vehicle. The sophisticated on-line fuel flow meter and GPS were used to collect real time fuel consumption and distance data that was integrated through a data acquisition system. In the present study an attempt has been made to investigate the variability in fuel consumption under various steady speeds. For this various test runs were carried out. The results emphasize that the coefficient of variation in fuel consumption ranged from 2% to 8% and the corresponding optimum fuel consumption was observed at 40 km/hr , 50 km/hr and 60km/hr speed. Present study findings reveal that even under controlled conditions, variability in fuel consumption is inevitable.