How often or how many kilometers should the antifreeze in a car be replaced?

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For small cars, high-quality antifreeze is generally replaced once a year. For cars that run for long periods, such as taxis, it can be replaced every two years or every 30,000 kilometers. Antifreeze prevents the coolant from freezing and cracking the radiator or damaging the engine cylinder block or head during cold winter parking. To avoid excessive foam formation, which reduces the heat exchange efficiency between the antifreeze and engine components, ensure the product is within its validity period when adding it. Long-lasting antifreeze can remain effective for up to three years. If suspended particles, sediment, or signs of deterioration or discoloration are found in the antifreeze, it should be replaced promptly, and the system should be cleaned. How to choose antifreeze: The basic indicators of antifreeze are its freezing point and boiling point. On the market, antifreeze is available with freezing points of -15°C, -25°C, -30°C, -40°C, etc. It is advisable to choose an antifreeze with a freezing point at least 10°C lower than the lowest temperature in your region. Can different antifreeze brands be mixed? Only antifreeze of the same brand should be used. Different brands may have varying production formulations, and mixing them could lead to chemical reactions between additives, rendering them ineffective.