Ah ha! :bonk: You're an "Amsoil guy". LOL- Interesting. Being relatively new around here, I didn't realize that. Nothing wrong with that in my opinion. Some of the Amsoil people I've talked to have an "Amsoil is the only lube to use..." attitude, which I personally do not agree with. I do however like the fact that they stipulate that any oil is only as good as the filtering system- which I believe to be correct.
I ran my 99' Buick Regal 6-8K miles between oil changes. My 04 Lesabre commonly runs 10-12K miles between oil changes. I use the onboard system set at "severe" parameters...and keep an eye on it. It's got 108K on it and runs like a top! (Based on my research and experience with them, GM seems to be one of the few, if not the only Auto OEM that got the oil monitor system correct.) I will do the same with my 4R. UOA is the only way to know for sure, but I'll bet dinner that the lubricant/filter I use is OK to the mileage intervals I use for changeout. Dang...that sounded kind of ignorant...sorry!
Also, I only use a Group IV (5W30 synthetic) motor oil and Pure One filters. When in doubt if I can't manage an oil change (it gets cold around here once in awhile) I change the filter and refill.
RW