LEST we get TOO carried away with the "Sacredness" of oil formulations as used by the refiners, let's DO sorta keep things in perspective... :-laf
WERE the ORIGINAL CI oils "perfect" as far as refiners - and their customers - were concerned - and if NOT "perfect", what might be done to make them BETTER?
WELL, a number of them next introduced the "Latest and greatest", and called it CI4 Plus...
And WHAT did they change to make the newer stuff "better"? They (GASP!) included new ADDITIVES to the existing package, in the case of Chevron Delo, that was Molybdenum and Boron - which made the CI4 Plus, in my opinion, the absolute BEST Dino-based oil available for use in my truck!
Keep in mind that oil companies are forced by circumstances and government regulations, to provide pretty much a SINGLE oil formulation in various grades, that will MOST CLOSELY provide the best service in a wide variety of climates and uses - from constant heavy loads in desert heat, to light usage in Arctic cold - as well as to conform to emission regulations.
Do any here REALLY think that a SINGLE grade oil will give the absolute BEST service in so widely differing scenarios - and that there couldn't POSSIBLY be any available benefit from addition of carefully selected additives to more closely "tailor" a specific oil to specific engine usages or customer goals?
Additives using stuff like Moly and Boron had been available LONG before Chevron Delo started using them in their own refining process - was it "Snake oil" prior to that time, or just not as acceptable, Politically Correct, UNTIL the oil companies "blessed" it, and started to use it themselves?
Sure, care and caution need to be exercised in adding to or changing what our oils already provide - but are those oil company formulations REALLY "Sacred", with NO likelihood of improvement in specific applications? I seriously doubt it - JUST AS I also seriously doubt that EPA dictates that have now REMOVED various former protective additives, have magically made them BETTER than before...

:-laf