[Piotrsko]

Well you can go buy the test kit at a parts store for your color of coolant. Primarily they check to see if the glycol is at the proportion it needs to be at for freeze protection, distilled water is more efficient in the summer. And yes I know that glycol increases the boiling point, but how often do you get that hot? Shouldn't ever need to. Up side is that coolant can last for a long time.

The coolant I use in the F250 is rumored to be million mile rated, but needs to be tested every 300,000 to see if the anti (bubble*) additives are still at effective levels

*destructive cavitation

Except for the new silicone brake fluid, the old alcohol based Dot 3 & 5 sucked up water which rusted the internals and caused leaks past the seals. Wasn't much of a problem in sealed systems. Everything else is mostly time neutral