There is a lot of good info. on these posts, and it's good to know that most of us really care about our cars. While reading through, I was reminded of a friend of mine that is a Navy engineer. We both ride motorcycles and argued about oil all the time. He had a Honda with 90,000 miles on it. That's a LOT of miles for a motorcycle, and he rode it like he stole it. He thought I was annal about oil for no reason. He said in his training at Georgia Tech, and in the Navy, he has never expericeced, or heard of a bearing failure that was the result of the oil used, or how old it was, as long as it was the right weight. As long as the surface has oil, it's lubricated. You either have lubrication or you don't. He would buy whatever oil was on sale.
Not my opinion, but I could never convince him otherwise.