While I can't directly answer your questions I would speculate that Nothing was actually wrong with the oil. I think most people on this board are really obsesed with having the best product available or at least something above the general curve. (nothing wrong with that) Like I said, I'm sure nothing wrong with the oil and having good maintance practices is what carried you so far. My father drove a 92 caravan for 220,000 miles on 3000 to 5000 mile oil changes using only valvoline and fram oil filters. Valvoline is frowned upon on this board as having very weak additive packages which looks to be true by VOA's and Fram is definatley a no no. But even on some 5000 mile oci's valvoline and fram held up enough to carry his van. (it was actually running until the water pump gave out and overheated it cooking the head.) Even knowing this, do I use valvoline and Fram? nope. I too want what's better or best for my vehicles so I run M1, Halvoline, and Napa (wix) filters. Are even these the best, probalby not but it's getting me above the curve and will hopefully help me easily reach very high mileage. No use dwelling on the past. Halvoline now is certainly very good as are many other choices. Good luck and have fun being obsessed with the rest of us. After all isn't that why most of us frequent this site?
