What Are the Effects of Diluting Antifreeze with Water?
3 Answers
After adding water to automotive antifreeze, the performance of the antifreeze will decrease. The full name of antifreeze is antifreeze coolant, meaning a coolant with antifreeze properties. Antifreeze prevents the coolant from freezing and expanding in cold winter conditions, which could otherwise crack the radiator or damage the engine block or cylinder head. Functions of Antifreeze: Antifreeze is a coolant containing special additives, primarily used in liquid-cooled engine cooling systems. It offers excellent properties such as preventing freezing in winter, boiling in summer, and providing year-round protection against scale and corrosion. Composition of Antifreeze: The main components of antifreeze are 50% pure water, 40% methanol, and 10% other substances. Types of Antifreeze: Antifreeze is generally divided into three types: ethanol-water type, glycerol-water type, and ethylene glycol-water type. Can Different Antifreeze Brands Be Mixed? It is necessary to use the same brand of antifreeze. Different brands of antifreeze may have varying production formulas, and mixing them could lead to chemical reactions between multiple additives, rendering the additives ineffective.
My dad, who has been driving for over 30 years, always reminds me of this: Mixing antifreeze with water randomly is like destroying your car! It might seem fine in summer, but when winter hits with temperatures below minus ten degrees Celsius, you're in trouble. Adding water raises the freezing point, turning it into ice blocks that can crack the radiator. My neighbor learned this the hard way, spending nearly ten thousand yuan to fix the engine. Even in emergencies, only distilled water should be used—tap water contains calcium and magnesium ions that can clog the radiator with scale in just three months, like cholesterol blocking blood vessels, causing the engine temperature to skyrocket while driving. The safest bet is to buy new antifreeze directly; the green bottles at the supermarket cost only about fifty or sixty yuan.
The veteran mechanic at the repair shop explained the principle to me: The performance of antifreeze is determined by the concentration of ethylene glycol. Diluting it with water significantly raises the freezing point, which is particularly dangerous—in Harbin, where temperatures drop to -30°C, it can crack the engine block. The boiling point also drops from 128°C to just over 100°C, causing the radiator to bubble and boil in summer traffic jams, with the dashboard warning light turning red and making people panic. Metal components are also prone to rust, and I've seen the water pump impeller jammed by scale several times. For short-term emergencies, you can add a bit of purified water, but remember not to exceed a 30% ratio. Before long trips, always check the fluid level and concentration—just swing a hydrometer a couple of times at the repair shop to measure it.
