Can Water Be Added to Antifreeze?
2 Answers
You can add an appropriate amount of distilled water or soft water, but excessive addition should be avoided as it may increase the freezing point of the antifreeze. Below are the functions of antifreeze: 1. Freeze protection: The freezing point of water is 0°C, while antifreeze typically has a freezing point below -25°C. In cold winter conditions, it prevents the coolant from freezing, which could otherwise cause the radiator to crack or damage the engine cylinder block. 2. Boil-over prevention: Antifreeze has a higher boiling point than water, effectively preventing the engine from "boiling over." 3. Prevention of scale formation: Scale is caused by insoluble salts or oxide crystals adhering to the inner surfaces of the cooling system. The main components of scale are calcium sulfate, calcium carbonate, and magnesium carbonate. High-quality antifreeze is made with distilled water and contains anti-scale additives, which not only prevent scale formation but also help remove existing scale.
As someone who has worked with cars for a long time, I can tell you that adding water to coolant is absolutely not recommended. Coolant isn't just for preventing freezing—it also prevents engine overheating and corrosion of internal metal components. If you casually add water, especially tap water, it dilutes the coolant concentration, causing the freezing point to rise (making the engine prone to cracking in winter) and the boiling point to drop (leading to engine overheating in summer). Worse still, minerals in tap water can form deposits that clog pipes, and the loss of anti-corrosion additives can cause the water pump to rust and fail. I've seen too many cases where car owners tried to save a little money by adding water, only to end up spending a fortune on repairs later. In emergencies, like when the fluid level is critically low, you can add distilled water temporarily, but you should thoroughly flush and replace it with fresh coolant as soon as possible. Always use the manufacturer-specified coolant or pre-mixed products, check the fluid level regularly to ensure safe driving, and avoid small conveniences that lead to big risks.
