This is the reason green antifreeze should be changed every two years or so. Aluminum is especially vulnerable to corrosion, and many vehicles have aluminum heads, radiators and other components in the cooling system. Many engine manufacturers currently use a new product. This orange antifreeze is an extended life antifreeze that increases the useful life of engine coolant. It is ethylene glycol-based but contains a different type of corrosion inhibitor that has a much longer life than silicates, phosphates and borates.
Orange antifreeze contains organic acids that protect engine parts from corrosion.
Don't mix the green, silicate-type antifreeze with orange antifreeze, Donald adds. The organic acids in orange types will cause separation of silicates in the green type, which greatly reduces corrosion protection. Orange antifreezes are useful coolants for five years or 100,000 miles in vehicles manufactured after 1995. They can be used in older vehicles if all of the green antifreeze mixture is thoroughly flushed from the system first. Useful life is about four years or 60,000 miles in older cars.