Car Myth Busters #30: New coolant with every oil change By Frank-Ling / Apr 04, 2014 share Facebook Twitter Google + LinkedIn Pinterest Email Share... By Frank LingWhen you take your car into the shop for an oil change you may have been given a “checklist” of what the shop found during your free auto check.In some quick oil change shops they’ll try to up-sell you on a radiator flush and coolant exchange while you’re there. These quickie shops will also try to sell you the idea that you’ll need new transmission fluid, a new O2 sensor, and an assortment of other unneeded services.But the one about flushing out your radiator sounds plausible and there is advice circulating around car buff forums that you should flush and fill with every oil change. So is this advice good or should it be flushed?Don’t botherMost car manufacturers recommended a radiator flush and fill every 4 years or so. In some cases this can be even longer. The reason for this long period between flushes is due to the modern characteristics of engine coolant or antifreeze.The better ones have anti-corrosive elements added to the basic antifreeze and will help your radiator and water pump last longer.Some car enthusiasts feel that a total change of the antifreeze in the car should be at intervals of every 24,000 miles. While this can certainly do no harm to the car, it can be an unnecessary additional expense.Check with your car manualSome cars and trucks may need more frequent coolant changes so the best bet, if you are in doubt, is to check your car manufacturer’s service recommendations for this service.When adding antifreeze be sure that it is mixed in a 50/50 percentage of water to coolant. In some cases products are already mixed to this ratio so be sure if you are buying the concentrated form or the premixed product.Different brands of antifreeze claim to do certain things, but in general any major brand will provide the radiator protection you need. Stay away from off-brands and bargain products just to be safe.Source: CarTalk.com