The role of information systems for environmental sustainability has received considerable attention over the last several years. In view of global warming and climate change, a transition from combustion to electric vehicles (EVs) can help reduce greenhouse gas (GHG) emissions. Since sustainable behavior often lacks relevant information about its environmental effects, the role of information systems in influencing energy consumption is being explored in this paper. The main focus is to investigate the impact of driver assistance systems in form of mobile applications on the energy consumption of EVs. To test such an impact, a field experiment is conducted by defining a control group and an experimental group. Test drives are performed with an all-electric, lithium-ion battery powered, small passenger city car. As the treatment of the study, a mobile application is chosen that monitors excessive acceleration and hard braking. The results reveal significant differences among the groups, which indicate that using smartphone-based driver assistance systems significantly reduces the energy consumption of EVs. This can entail several benefits, including an increase of range of EVs, electricity cost savings, decrease of vehicle wear, and reduction of GHG emissions. The findings are discussed and implications for research and practice are given.