This article investigates the effects of different characteristics of supplier–customer relationships in the Japanese automotive industry, and how these influence predictions about future technologies of a disruptive nature, such as Electric Vehicles (EVs). We conducted a survey of a broad set of suppliers in the Japanese automotive industry and another survey of suppliers registered with Toyota's two supplier associations. The data were used to analyse the influence of particular relationships and practices on information gathering about new technologies, preparations for R&D and production of new components, and predictions about new technologies. The study shows that suppliers’ R&D intensity and the usage degree of the drawing-supplied parts system lead to predictions favouring the uptake of new technologies. Moreover, communication between automakers and suppliers and arm's-length relationships simultaneously lead to favourable views on the future of new technologies, especially with regard to EVs. Moreover, we find that Japanese-style cooperative relationships, arm's-length relationships, communication between automakers and suppliers, and communication among suppliers all lead to less favourable views on new technology uptake (in this case, EVs). We discuss the implications of these findings for research and practice, specifically for EVs.