How Long Can Antifreeze Be Used?
3 Answers
Vehicle antifreeze generally needs to be replaced every 2 years or 40,000 kilometers. This is just a reference interval. For commercial vehicles with higher mileage, the replacement cycle should be shorter. Since driving conditions vary for each vehicle, the replacement should be based on actual usage. Check the antifreeze condition; if it is insufficient, replenish it promptly. If suspended matter, sediment, or signs of deterioration or discoloration are found in the antifreeze, replace it immediately and clean the system. Types of Antifreeze: Antifreeze is generally classified into three types: ethanol-water, glycerol-water, and ethylene glycol-water. How to Choose Antifreeze: The basic indicators of antifreeze are its freezing point and boiling point. The market offers antifreeze with freezing points of -15°C, -25°C, -30°C, -40°C, etc. Generally, it is advisable to choose antifreeze with a freezing point at least 10°C lower than the lowest temperature in your region. Functions of Antifreeze: Antifreeze is non-corrosive. It is a coolant with special additives, mainly used in liquid-cooled engine cooling systems. Antifreeze has excellent properties such as preventing freezing in winter, boiling in summer, and offering year-round protection against scale and corrosion.
I just finished dealing with the antifreeze issue in my car. The shelf life of this stuff really depends on the specific situation, with manufacturers generally recommending between 2 to 5 years. Last year when I helped my neighbor check his car, I found that the three-year-old green antifreeze had turned rust-red, with a freezing point test showing only -15°C. What people often overlook is that antifreeze slowly absorbs moisture, causing the rust inhibitors to fail, which leads to internal radiator rust. I make it a habit to test the pH level with test strips before winter each year, and replace it early if the color changes too quickly. Also, modified turbocharged cars require special attention, as high engine temperatures can cause antifreeze to degrade more easily.
Last time at the repair shop, the master mechanic mentioned that many new cars now come with long-life coolant that can last up to 5 years, but in reality, it depends on the driving environment. In northern regions where winter temperatures drop to -30°C, I recommend changing it every two years. Here's a handy self-check tip: open the radiator cap to see if the fluid is cloudy and check if rubber hoses have turned reddish-brown. I've seen cases where owners tried to save small money but ended up with big losses - expired coolant corroded the water pump impeller, costing about 700-800 RMB to repair. Remember to check the freezing point when selecting coolant - for our northeast region, we need to choose -45°C rated coolant for safety.
