Ethylene glycol-based coolant technologies for automotive applications: A critical review

Coolant fluids have been in use for almost a century. The use of cooling fluids is essential for heat transfer applications serving various purposes, such as protection against overheating or freezing. However, due to the heat stress conditions that occur inside such systems, these cooling fluids can also contribute to problematic issues, such as scaling/deposition of inorganic salts, and/or corrosion of critical equipment surfaces. The imperative to optimize the performance of coolant fluids has become increasingly pronounced. The dynamic changes in industry, technology, and environmental standards increased the demand for coolant formulations that not only deliver enhanced performance but also align with evolving global needs. This has led to an ongoing process of refining and optimizing the coolant technologies to meet the escalating requirements of a rapidly evolving world. In this review, our aim is to deliver a thorough and in-depth coverage of the ethylene glycol-based cooling fluids and the different coolant technologies used over the years. Through a meticulous examination of key concepts, recent advancements, and critical insights, this paper seeks to underscore the critical importance of coolant composition in determining the efficiency, material compatibility and sustainability of these products.