Originally Posted By: ZZman
Oil companies develop motor oils with a balance in mind of performance, cleanliness, fuel economy etc. This made me wonder if many of the additives that have large amounts of things like detergents, moly, boron, ZDDP etc are actually not good and affect the balance negatively that the motor oils are meant to have.
Your thoughts?
Your wonderings and assumptions are correct. They are (in general) not good for the balance and will negatively affect performance in some way. It might not be obvious but they are rarely benign and even more rarely beneficial.
An improvement is not impossible, but it is both unlikely and unrepeatable if attempted by another person in another car. If an improvement were obtained, it would be out of pure random luck that the specific concentration of that specific additive worked synergistically with the existing additives of the oil (Yes, synergy between additives is real and not just a buzzword, but they are very carefully selected by formulators).
As kschachn mentioned, the additive manufacturers have no idea what original additives they are top treating to make it suitable universally, and therefore, it is a complete shot in the dark with the odds very much stacked against it to be effective in any way.