Modeling effects of vehicle specifications on fuel economy based on engine fuel consumption map and vehicle dynamics

The present study conducts a vehicle dynamic modeling of gasoline and diesel vehicles by using the AVL commercial program. 10 passenger vehicles were tested for 7 types of driving modes containing city, express and highway driving mode. The various vehicle data (specifications, fuel consumption map, gear shifting curve data, etc.) were collected and implemented as input data. The calculations were conducted with changing driving modes and vehicle types, and prediction accuracy of the calculation results were validated based on chassis dynamometer test data. In order to increase prediction accuracy for a wide vehicle operating range, some modifications regarding gear shifting was also conducted. From these processes, it is confirmed that the prediction accuracy of fuel efficiency and CO2 emissions shows a strong correlations with test results. After ensuring the accuracy of the calculation result, parametric studies were conducted to reveal correlations between vehicle specifications (e.g., vehicle weight and frontal area) on fuel efficiency and CO2 emissions and check which parameters were highly impact on fuel efficiency.