Conducting research on user-energy interaction in automotive systems in controlled settings is challenging due to the lack of availability of low-cost driving simulation environments that enable both (1) a precise simulation of vehicle energy dynamics and (2) a high-fidelity representation of the driving environment. This Extended Abstract presents EcoSimLab, a driving simulator environment for rapid prototyping, testing and evaluation of energy interface and eco assistance design concepts as well as for comprehensive studies on eco-driving behavior and further facets of user-energy interaction. We present the system architecture based on BeamNG.tech, initial data on usability and energy model validity, and we discuss future enhancements and potential applications of EcoSimLab.