Supporting energy-efficient driving is essential for sustainable mobility in electric vehicles (EVs), where operational eco-driving (or ecodriving) can significantly reduce energy consumption. This study investigates the effects of two types of ecodriving displays—an Instantaneous Consumption Display (ICD) and an Optimal Speed Display (OSD)—on energy consumption and energy-related situation awareness (Energy Dynamics Awareness, EnDynA). In the EcoSimLab EV simulator, N = 94 participants were assigned to the ICD, OSD, or a control condition and completed multiple driving trials with varying situation complexity. Improvement, defined as the difference between the display and baseline conditions, in EnDynA and eco-driving performance, was greater in the display groups than in the control. The OSD, providing predictive speed recommendations by dynamic programming, was particularly effective in more complex driving scenarios. The ICD, offering real-time consumption feedback, facilitated learning in simpler scenarios. Findings underscore the importance of adaptive ecodriving support systems, balancing real-time feedback with predictive guidance.