Engine coolant is a fluid used in vehicles to regulate engine temperature. It absorbs heat from the engine and dissipates it through the radiator, preventing overheating. Typically, engine coolant is a mixture of water and antifreeze, which helps to lower the freezing point and raise the boiling point of the fluid. In addition to temperature regulation, engine coolant also protects the engine from corrosion and deposits. It contains additives that help maintain the integrity of the engine components, such as the radiator and water pump. Regular maintenance of engine coolant is essential for optimal vehicle performance.