Originally Posted By: atoalson
... which of the big three brands is the standout leader? I'm referencing Delo 400, Delvac 1300 and Rotella T4, all 15W-40 flavors.
Ummmmmm ......
What makes you think there is a "standout" among the three, or any other brand for that matter?
Please, take some time to read this:
https://bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/
Not one person here has enough info to tell you with even a smidgen of a fraction of a guesstimate as to which is a standout, "better" or superior/inferior. CK-4 has been out a short time. No one here has enough time/money to really study this, and answer your question with any clarity or evidence. And frankly I see no reason to believe this most recent level of API cert (CK-4) would have any different true performance delta in the market in terms of brand "best-ness" as any former level. There was no "best" CJ-4, or CI-4+, or ... They are all good. They all are likely to be well more than you need for your application.
That being said, I'm sure several here will bench-race this lube to the nth degree, and either convince you based on their strong subjective influence, or just rub you the wrong way and against their favorite flavor.
When you're done reading that link above, re-read it. Read it until you get the real point.
To prove what is "best" takes HUGE amounts of time and money; not one person here I'm aware of has the pool of resources necessary to prove what is "best" in their own application, let alone everyone else s ... If you cannot do it for yourself, why would you believe that someone else has the ability?
There is zero reason to believe that any CK-4 is going to be so much "better" that it will "stand out" from the others, for any normal person's application.