I have an 02' Ford Excursion 6.8 V10 with 253,000 miles and during the last couple months of winter I've noticed that the coolant level slowly goes down from the "full" level over the period of a couple weeks and I keep it topped off. Runs like a top, never has an issue starting, slightly white smoke on startup but that seems pretty normal being as far North as I am it gets down to the single digits most nights and there's not very much of this smoke even while driving. Is this anything to be concerned about or just chalk it up to old age and cold climate? Absolutely love my Excursion so I hate to think it may be time to think about getting rid of it. Thanks again everyone!