Don't know about their additive but Lucas oil products were at the very bottom of the test sheet with the worst performance of all, along with Royal Purple and a couple others. Additives are snake oil in my opinion anyway. Nothing you add to the Amsoil or Mobile is going to improve it's performance and in some case will even hinder it.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!