Jack:
Alliterative allusions to altruistic alternative algorithms are always appreciated!
Really, no flame wars, divisive arguments, or attempts to be "right" on this issue, just fun discussion.
In that spirit, "scientific fact" is described in the scientific method as "best current consensus until contradicted by new evidence". By that definition, 5000-7000 mile change intervals are "best", because that is the manufacturers and oil companies recommendations.
There are always a few scientists on ANY topic willing to try to provide evidence against the current consensus. I enjoy tilting at the occasional windmill, and the concept of having a car tell me that 15000 miles is OK on the oil change is too tempting to resist. Also, the research grants offered to universities by manufacturers often have lots of strings and "suggested research directions" attached, so I am probably more cynical about company motives than is normal or appropriate.
I hope there are no bruised feelings out there, just enjoying the discussion and trying to learn!
Here are a couple of interesting sites on oil analysis and additives for anyone interested.
http://www.wearcheck.ca/FYI/WearCheckFYI.htm
http://www.gsresources.com/additives.oil.html