Model for optimizing energy efficiency through controlling speed and gear ratio

Specific fuel consumption of vehicles has been improved through technical changes in the last three decades. There has been little study of the impact of behavioral aspects on the specific fuel consumption of vehicles. Analytical tools developed recently have included options for quantifying the specific fuel consumption in certain predefined driving cycles. Empirical studies have shown that real driving cycles are different from predefined ones. It has also been observed that optimal coordination of both speed of vehicle and gear ratio are detrimental to the improved performance of a vehicle. Previous studies have only considered the vehicle speed as the explanatory parameter, and gear ratio has rarely been discussed. Therefore, an optimal model of vehicle fuel consumption has been developed on the basis of microeconomic theories. The application of this model helps to identify the optimal driving strategy of a vehicle in a certain real driving cycle. The model has then been applied to estimate the optimal fuel consumption of a vehicle in a given real case, and the results of model estimate have been compared with measured data. It has been found that the implementation of optimal driving strategy based on the model estimates may help to reduce specific fuel consumption by 3.2 l/100 km on average (37% of actual specific consumption). It is also observed that the potential for energy saving prevails when the traffic flow is dense and slow. Hence, the implementation of optimal driving strategy based on the coordination of speed and gear ratio would lead to the realization of energy saving potential that is considerable.