Now that you know how it works and its importance in maintaining your car, the next question begs how long coolants last in a vehicle. Unfortunately, there is not a one-size-fits-all answer to that question. Some say you have to change it every three years, while others believe it is best to flush the radiator fluid annually. There is a consensus that if your car is new and has only achieved less than 10,000 miles, there is no need to perform a flush. Beyond this, there are different factors to consider when determining whether it is time to flush your car radiator’s fluid. Generally, car makers recommend changing yours every 30,000 miles. However, your driving habits also play a role in knowing the frequency of your radiator’s fluid changes. For example, suppose you frequently use your vehicle under extremely hot conditions. You may have to flush the radiator fluid every 12,000 to 15,000 miles, or about once a year. Your brand and model are other factors. Some Mercedes-Benz models need a fluid flush within a 30,000-mile interval, while others can last up to 120,000 miles. Meanwhile, coolants on most Chevrolets last after every 150,000 miles regardless of driving habits. It is typically advised to flush it after 160,000 kilometers, or 100,000 miles for modern cars. In contrast, others may need a shorter mileage than this. You may want to consult your user manual or check with your vehicle manufacturer if you are still unsure when to change it.