If you use an aluminum radiator, you need to do something to protect it against corrosion. You should use a coolant designed to protect aluminum, but we also recommend the use of a sacrificial zinc anode. The zinc is attacked and corrodes before the aluminum. You’ll need to change the coolant and the anode every 4-5 years. Some of the manufacturers of aluminum radiators offer these anodes or coolant additives that protect against corrosion.