How often should the coolant in a car be replaced?

[RileyMarie]

Automotive coolant should be replaced approximately every 2 years or after driving 40,000 kilometers. For commercial vehicles with higher mileage, the replacement interval should be shorter. The coolant replacement procedure is as follows: 1. Unscrew the radiator cap and open the radiator drain valve, typically located at the bottom of the car, to drain the old coolant. 2. Clean the engine cooling system by continuously flushing it with clean water. During this process, keep the engine idling to ensure water circulation until clear water flows out from the radiator. 3. Stop adding water and wait until it completely drains, then close the drain valve. 4. Refill with new coolant to a level between the MAX and MIN marks. 5. Securely close the cap, start the car, and let the engine idle for 2-3 minutes. The cooling system will purge air, causing the coolant level to drop slightly, at which point additional coolant should be added.

[SanJoel]

I've been driving small cars on long trips for many years, and it's best to change the coolant every two years, depending on the car model and usage. In summer, coolant also helps the engine dissipate heat to avoid overheating issues; in winter, it prevents the radiator from freezing and cracking. I once tried delaying the change for three years, and the fluid level dropped, the color turned cloudy, leading to costly repairs. If the color turns yellow or becomes cloudy, it means the coolant has deteriorated—replace it immediately. Don’t slack off; check the fluid level and pH during annual maintenance to ensure it stays clear and transparent. Parking in the shade can also extend its lifespan since high engine temperatures can degrade the coolant. Regular maintenance saves hassle and keeps you safe.

[TheoLee]

As someone who enjoys tinkering with mechanics, I emphasize that the antifreeze replacement cycle is generally around every 40,000 kilometers or two years. Its additives will decompose, leading to corrosion inside the radiator and reduced cooling efficiency. If left unchanged for a long time, the ethylene glycol content may drop, potentially causing freezing or boiling too quickly. I've seen a friend's car suffer engine failure due to old antifreeze, costing over 4,000 yuan in repairs. You can use test strips to check the changes in freezing and boiling points during inspection; switching to long-life coolant can also save some hassle. Remember, different car brands' manuals may have different recommendations, but frequent checks and timely replacements are key to extending your vehicle's lifespan. Don't wait until problems arise to regret it.

[SanFernando]

From a safe driving perspective, antifreeze needs to be replaced regularly to prevent accidents: when it deteriorates, it may freeze the engine in winter and cause overheating breakdowns in summer. It is recommended to replace the fluid every three years and check the fluid level and color—clear green is ideal, while cloudy or discolored fluid indicates action is needed. I once experienced engine smoke during a long trip due to not replacing the fluid on time; simple maintenance is more reliable in avoiding major accidents.