There are quite a number of myths pertaining to car maintenance that are baseless. Consider, for example, the belief that you must you must change your oil every 3000 miles; this is a money-making gimmick by oil marketers. For the most accurate mileage when it's time to change your engine oil, consult your vehicle's manual. When it comes to your car's cooling system, they say that you should flush your engine's coolant every time you change the oil. Most manuals advise that you do so after about five years or 60,000 miles. However, if your engine coolant is low, you should check for any leaks and probably top off your fluids.