Can blue antifreeze and green antifreeze be mixed?
2 Answers
Blue antifreeze and green antifreeze cannot be mixed, and the same brand of antifreeze must be used. Different brands of antifreeze have different production formulas. If mixed, chemical reactions are likely to occur between various additives, rendering them ineffective. Vehicle antifreeze generally needs to be replaced every 2 years or 40,000 kilometers, which is just a reference period. For commercial vehicles with longer mileage, the replacement cycle is shorter. Since driving conditions vary for each vehicle, the replacement should be based on actual usage. Check the antifreeze's condition; if it is found to be insufficient, replenish it promptly. If suspended particles, sediment, or signs of deterioration or discoloration are observed in the antifreeze, replace it immediately and clean the system. 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. Generally, it is advisable to choose one that is at least 10°C lower than the lowest temperature in your region.
I've run an auto repair shop for twenty years and seen countless engine issues caused by mixing coolants. You can't randomly mix blue and green ones because they might have different formulations, like Organic Acid Technology (OAT) and Inorganic Additive Technology (IAT). Mixing them can easily cause sediment buildup, clogging the cooling system and corroding the radiator and engine components. Once, while helping a customer, they mixed coolants to save money, and the engine overheated—costing a fortune to fix. It's best not to take that risk. Always use the same brand and color when changing coolant, or thoroughly flush the system before switching. Regularly checking the coolant condition can prevent problems, and replacing it every two years is the safest bet.
