I did and the only support to the idea that old oil is better oil is to the following SAE paper:

Antiwear Performance of Low Phosphorus Engine Oils on Tappet Inserts in Motored Sliding Valvetrain Test

I'm not going to spend money on the paper, but reading the title and abstract indicates to me that this is hardly a general test to indicate that running old oil in an engine improves wear characteristics.

I'll also note that the very first paragraph in the quoted web site states, "Mobil 1 currently enjoys the distinction of being the only readily available true PAO synthetic motor oil." which is simply not true.

I'm not a believer that changing oil more frequently than the mfg recommends is necessarily a good idea, but frankly this 8K-15K change interval with filter changes every 5K recommendation is pretty wacky. A 5K filter change interval makes about as much sense as a 3K oil change interval, which is not much. And the mfgs who recommend different filter vs. oil change intervals generally recommend that filters be changed less often rather than more. It's pretty hard to come up with any rationale explanation why an oil filter on an average car needs to be changed at 5K intervals.

So all in all, a pretty silly technical article, even by the low standards of oil articles in general. I don't think you can go too horribly wrong my simply following the mfg's recommended change intervals, or since Mini's tend to have somewhat uncomfortably long recommendations, maybe halve them, which on my car means I change oil/filter every 8K or so.

- Mark