With the continuous advancement of artificial intelligence technology, the automation level of electric vehicles (EVs) is rapidly increasing. Despite the improvements in travel efficiency, safety, and convenience brought about by automation, cutting-edge intelligent technologies also pose the potential of increased energy consumption, such as the computational power required by advanced algorithms and the energy usage of high-precision equipment, leading to higher overall energy consumption for connected or autonomous electric vehicles (CAEVs). To assess the impact of intelligent technologies on AEVs, this study innovatively provides a comprehensive evaluation of the impact of intelligent technologies on CAEV energy consumption from both positive and negative perspectives. After reviewing 59 relevant studies, the findings highlight energy savings achieved through Vehicle-to-Infrastructure and Vehicle-to-Vehicle cooperation as positive effects, while increased energy consumption from complex equipment and intensive computational tasks associated with intelligent algorithms are noted as challenges. In addition to providing a comprehensive overview of the existing impacts, this study concludes the review by proposing the most promising research directions to address these factors. For example, this study indicates that computer systems in autonomous driving account for the most significant proportion of increased energy consumption, reaching approximately 41%. In contrast, strategies such as car-following and lane-changing might reduce energy consumption by up to about 37%. Therefore, integrating these approaches can help balance the overall energy consumption of vehicles.