Originally Posted By: WobblyElvis
Been maintaining older cars for the past 45 years. In the past 20 years the coolant has advanced significantly and I find a rad flush and new fluid is not necessary at all. I don't know how they do it but it is far better than it used to be. In my experience going 10 years on the original fluid is very doable. If I kept a new car 20 years, I would only expect to service the cooling system fluid once and that's it.
Agreed. With the old plain green coolant, I never had a corrosion issue with a radiator drain and refill every 2 years.
With the new fluids, you could likely do the same every 4-5 years and be well protected.