To make matters worse, I've done oil analysis for nearly 2 years on a Gen 3 engine using MS-12991 oils exclusively and I have seen iron and aluminum levels that are higher than universal averages. The last oil I ran was Motul, which is supposed to be a top-tier oil, and it performed exactly the same as the cheap off-the-shelf Walmart oils.
It appears that Rotella T6 may reduce wear on the Gen 3 engine, but at the expense of losing warranty. The spec'd oils protect warranty, but at the expense of engine life. The owner of the truck is over a barrel. It sucks.
My next oil will be the Quaker State Ultimate Durability 5W40. $17 per 5 quart jug at Walmart. MS-12991 rated. Virgin analysis shows a more robust additive pack. We'll see...