How Often Should Antifreeze Be Replaced ?

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Antifreeze should be replaced every two years due to oxidation and deterioration of important additives. These additives lubricate the water pump and protect metal parts from rust and oxidation. They also help keep coolant hoses soft and flexible. Today we can recycle and clean old antifreeze, replacing the additives. Antifreeze is very toxic and not environmentally friendly so recycling makes good sense. The engine's thermostat should also be replaced every 2 years to keep the engine operating temperatures in the proper range. 
 

Why Can't I Use Plain Water In My Radiator ?

Your car's engine makes enough heat to destroy itself so a cooling system is needed. Antifreeze mixed with water at a 50/50 ratio provides freeze and boiling protection. Too much antifreeze can cause heat transfer problems which can result in overheating. If you experience overheating, turn the a/c off and the heater on to help remove heat from the coolant. If the engine temperature light comes on or the gauge goes into the red zone, the engine should be turned off quickly and allowed to cool down to avoid costly engine damage. Plain water will start a rust process that is almost impossible to stop. Rust particles deteriorate the entire cooling system, water pump, radiator, hoses, thermostat etc.