How Long Can Unopened Antifreeze Be Stored?
2 Answers
Unopened antifreeze can be stored for three years. Antifreeze is a type of coolant containing special additives, used in liquid-cooled engine cooling systems. Its functions include: 1. Preventing freezing in winter; 2. Anti-corrosion; 3. Preventing scale buildup. The method for replacing antifreeze: 1. Unscrew the radiator cap and open the radiator drain valve to release the antifreeze; 2. Insert a rubber hose connected to a tap into the radiator filler port, allowing tap water to flow through the engine cooling system until clear water comes out of the radiator; 3. Turn off the tap, wait until all water in the cooling system is drained, then close the radiator drain valve; 4. Fill the radiator with antifreeze through the filler port, then unscrew the reservoir cap and add antifreeze until it reaches the 'max' mark; 5. Tighten the radiator cap and reservoir cap; 6. Start the engine and let it idle for about 2 to 3 minutes, then unscrew the radiator cap to top up the antifreeze until it reaches the 'max' mark, and finally secure the radiator cap.
I previously stocked up a few containers of antifreeze in my garage, and unopened, they can actually last quite a long time. I remember one container at home was stored for almost five years, and when I recently opened it to use, it was as good as new—poured out clear with no sediment. However, it's important not to store them in places like the balcony or trunk, as high summer temperatures can accelerate spoilage. The manufacturer's labeled shelf life of typically three to five years is a conservative estimate; if well-sealed, they should last six to seven years without issue. I always check the production date on the packaging when buying and recommend storing them on a cool, dry shelf. As long as they're not exposed to sun or rain, they last much longer than opened ones. Keeping the garage temperature stable below 25°C is the safest, and just use a flashlight to check the bottle bottom for any crystals.
