@Jim Gilbert - Madison, Mississippi I've often wondered that as well. Today's oil is worlds better than what it used to be. The only difference between my daily driver oil and my speedster oil is the Speedster oil has a much higher concentration of additives. (I think) I change my truck oil and Nancy's oil when the computer in the car says to. Her Porsche is 12 months or 10K miles and my truck is 15K miles.
I'm curious as to what the collective says but in the meantime I'll see if any molecular experts have weighed in on this.