It is a shame that he couldn't have just tried this and reported, as you are proposing. It's something that does interest us all.

My take is that oil analysis costs more than an oil change, and I wouldn't want to rely on a very long interval (not to mention no interval) without analysis.

But the big diesels run a lot more than 3K per change. They hold a lot more oil and use bypass filters, so this isn't a fair comparison.

I bet if you ask, you'll get some people who will help with some analysis costs. I may help myself, but I ask that you do the first one out of your own pocket.