How critical is to replace engine coolant. I put 80k on my focus 2000 SE, but never replaced coolant. Is replacing coolant going to help my car in any ways. The coolant level looks fine but when the car is cold and warm.
In my opinion the best antifreeze you can buy is Polypropylene Glycol (traditional coolant is Ethylene Glycol). You can Google the differences.
The Poly. coolant is usually a jug that will say something like 'safe for pets'.