Development of Driver Fuel Economy Index for Real Road Fuel Economy

Abstract

Although a 5-cycle testing was adopted to address the gap between the reported fuel economy from certification tests and fuel economy during real-world driving, the gap still remains and is difficult to be resolved without the consideration of the fuel consumption influencing parameters such as driver's behavior, driving pattern and road condition. In this study, two types of driver fuel economy indices, the MAW (Moving Average Window) Power Ratio Index and the Constant Driving Index are newly defined to invent the index which can reflect the real-road conditions and simulate the real-world fuel economy. Both indices are defined as the ratio of actual driving to ideal (constant speed) driving in common but the former is based on the engine output and the latter is based on the work. Two types of indices are verified with 5-cycle testing results on chassis dynamometer. According to the verification, the MAW Power Ratio Index with window size of 60 seconds shows the highest correlation with the certified fuel economy and is the reasonable starting point of index for reflecting the real-road conditions.