Test for assessing the energy efficiency of vehicles with internal combustion engines

The most popular method for assessing the energy efficiency of vehicles is to compare the fuel consumption achieved in the conditions of selected approval test. Operating conditions are defined using the speed profiles, usually for only two categories: urban and extra-urban driving. Assessing the energy efficiency of vehicles should be performed using a more detailed classification of conditions. Presented results of comparison of reference fuel consumption of five vehicles have showed that depending on driving style, the existing traffic problems and the average velocity, the differences in fuel consumption will change in a relatively wide range. The paper presents new test for assessing energy efficiency of vehicles powered by different fuels, which facilitates to perform analysis based on a single drive in a regular city traffic with the registration of the basic parameters of the engine and vehicle. Proposed test takes into account the full range of vehicle propulsion systems operation with using of specific tractive energy that takes into account both an influence of external conditions and driver's style of driving. Quantitative comparison of the energy efficiency of vehicles can then be performed using proposed in work index.