This study investigates the link between the presence of paradoxical thinking language in corporate sustainability reports and variations in companies' eco-efficiency, focusing specifically on the automotive industry. Based on the hypothesis that there is a relationship between paradoxical thinking and eco-efficiency, we aimed to identify which words are most likely to impact these emissions. We solicited the aid of ChatGPT to generate a potential list of impactful words and we tested this word list using sustainability reports from the automotive industry and the eco-efficiencies of these firms, spanning the years 2005 to 2023. Our analysis reveals a significant association between the usage of paradoxical thinking language in these reports and variations in eco-efficiency, showing that paradoxical thinking matters. Furthermore, our research links paradoxical thinking to two different strategies of dealing with the paradoxical tension between economic output on the one hand and lowering environmental resource use on the other hand. This research underscores the potential role of paradoxical thinking in corporate sustainability practices and suggests that specific language patterns in sustainability reports may influence practical environmental outcomes.