A UOA from Blackstone cost $35 bucks, about the same as an oil change using a PF-48 and Supertech 5w-30 from Walmart. My 2016 2500HD has a 6.0 vortec and usually the OLM tells me to change the oil at around 6500 miles.
If I want to extend my drain interval, I'd assume I'd go with a more expensive oil and filter, and then at 6500 miles or so send off a sample to be tested. But if I used Supertech and the PF-48, I could just change the oil for that price. So I guess I don't see really what I stand to gain - changing the oil isn't much more work than pulling a sample. Once I put on work clothes, pull the truck into the garage, and get my tools out, I feel like I may as well change the oil?
If I had to guess, maybe the benefits start to accrue after you do the first UOA. Assuming I used a premium oil and filter and the first UOA told me I could go another 6500 miles, then on the second OCI I don't bother to do a UOA - I just drive 13k miles straight without ever crawling under the truck.
Is that the theory behind UOA's and extended drain intervals, that once you do the first UOA you can safely extend the drain interval without doing another UOA for a while (say 50k miles)?