The ten year coolants are oat, meaning basically 100% ethylene glycol. Now dex adds some stupid stuff to this and comes in an orange container, just avoid that. The Asians also add things specific to their coolants phosphates and silicates or whatever. FCA uses pure oat the same thing as g30 or peak global life. So in theory they can last a lifetime as peak global says. I would change by color of coolant, or more to the point clarify of coolant. I find the oat's lose a little clarify at some point past 5 years. Kind of why I like working on ,my Toyota, they have a nice clear reservoir to look at. Easy to judge coolant and see when it is leaking, and yes it saved my bacon on a leak once. Look up and verify info, It's been a while since I looked, SDS should be easily available for any coolant.