What is the proper method for adding anti-freeze to an engine while it is operating?

Adding anti-freeze to an engine while it is operating requires using a method that ensures safety and effectiveness. Mixing anti-freeze with a small amount of water is the proper approach, as this method helps to lower the concentration of the coolant and prevents potential damage due to thermal shock. Engine components can be sensitive to sudden temperature changes, and diluting the anti-freeze reduces the risk of overheating or causing damage to components like the radiator and engine block.

Anti-freeze is designed to work optimally when mixed with water, as this combination enhances its performance properties, such as lowering the freezing point and raising the boiling point of the coolant mixture. A direct addition of concentrated anti-freeze without mixing can lead to inconsistent temperatures within the cooling system and does not provide the full benefits of what coolant should offer.

Using additional water also helps in achieving the proper mixture ratio, which is typically around 50/50 for optimal performance. Therefore, when adding anti-freeze to an engine while it is operating, thoroughly mixing it with a small amount of water ensures a safer and more effective approach for maintaining engine temperature.