I would still need convincing.........
I guess the old school thinking was change the oil every year regardless of how little miles, my feeling is that diesels still stock and not turned up may benefit from the extended change, but turned up they soot the oil quickly and the soot needs to be removed.
Now you could say that getting a bypass filter and using expensive AMSOIL filters will negate that argument, but I usually trade up every 3-4 years, I didn't because I was not impressed with the LLY's so I kept my 2002 and bought a 2007 LBZ instead.
My LBZ has 23K on it and I use Rotella 15W-40 dino oil at 4K intervals.
I would like to be convinced that AMSOIL is the holy grail of oils, but the added cost for me is not justifiable based on my past experiences with regular old oil.
Based on the web pricing an Oil/Filter change using AMSOIL is around $130.00 WITH SHIPPING, I can do 4 regular oil changes for the same money.