2 years on coolant and about 750 miles on it.

Premixed coolant uses distilled water, no need to add anything. Always thought that was a lazy 100% markup but when distilled water is .89 a gallon at Walmart, it makes sense to buy straight coolant and a jug or 2 of distilled water at the same time. Save your old empty jugs and premix in there. 2 for 1! I doubt the new stuff breaks down in under 5 years or 150k myself. 5 year Dexcool is class action lawsuit ****, but the newer OAT/HOAT stuff is way better. Use the green for brass radiators and heater cores. The OA is for Organic Acid, and that does break down over time.