Calcium disulfide as an oil additive? The Blackstone tech is very confused. Detergents are typically phenolates, phosphonates and sulfonates. These compounds are all weak acids that are rendered neutral by the addition of calcium or magnesium hydroxides and carbonates. Excess base is used in high TBN lubricants to provide extra buffering capacity in order to neutralize additional acids formed from fuel combustion products. Sulfuric acid is a combustion product that can form in the presence of water. When sulfuric acid is neutralized by the extra calcium in a high TBN oil, calcium disulfide can form. As the TBN of the oil becomes depleted, sulfuric acid can re-form if moisture is present. During storage, this will happen slower with a high TBN oil than with a low TBN oil.
In general, high TBN oils with excess calcium and/or magnesium reduce acid formation during storage. Vapor phase corrosion inhibitors are are part of the additive package of certain marine oils. However, I don't understand their chemistry.