Many manufacturers recommend you change the coolant every 30,000 miles. For others it may not even be listed on your maintenance schedule. For example many Hyundai models suggest it changed after the first 60,000 miles, then every 30,000 miles thereafter. Mercedes with some engines may be 30,000 miles and others it can be as high as 120,000 or 12 years. Many suggest it be changed more often if it is subject to severe service such as frequent towing. Many Chevrolet and other GMs recommend it at 150,000 miles regardless of how you drive it.
So how do I know when to change it? Well, many vehicles use a long-life coolant in the radiator and that can last for a few years with little to no maintenance. Many manufacturers were pressured to reduce the amount of old coolant that must be disposed of or recycled, thus why it is made to last a lot longer than it was prior. Coolant does deteriorate over time and should be tested to ensure it is still good, it is hard to tell by just the appearance.
Over time it looses the rust-inhibiting properties that can cause corrosion. This can damage your radiator, water pump, thermostat, hoses and other parts of your engines cooling system… eventually leading to your vehicle overheating. Therefore we recommend changing your coolant out or having it at least tested every 50,000 miles or once a year. If corrosion inhibitors in the coolant have deteriorated, the antifreeze must be changed no matter how many miles you have on it. It may also need to be flushed to remove contaminants. Prevention is always key. We would rather you change your coolant too soon than too late.
