Additive Elements

Boron is an EP (extreme pressure) additive but it is also found in coolants. Boron without the presence of potassium is an indication of an additive.

Barium as barium petroleum sulfonate can be used as a detergent in oil formulation as well as  corrosion inhibitors.

Calcium as calcium petroleum sulfonate is a detergent. It cleans carbon deposits from engines and acts as a corrosion inhibitor and dispersant. When burnt, calcium additives have an ash content of generally >1% in engine oil formulations.

Magnesium as magnesium petroleum sulphonate is also a detergent that leaves generally < 1% ash. It reacts with sludge and varnish  to neutralize them and keep them soluble.

Molybdenum may be present in some oil formulations as a solid lubricant additive (molybdenum disulfide) and may be used as an additive in grease. Soluble molybdenum additives are added to formulations in some cases.

Sodium is found as an additive in some instances as a detergent.

Phosphorus is found in extreme pressure (EP) as well as in anti-wear /anti-oxidant additives and friction modifiers in engine oils, hydraulic fluids and gear oils. 

Sulphur is found in extreme pressure additives in combination with phosphorus.

Zinc is part of ZDDP (Zinc Dialkyl DithioPhosphate) additive that acts as an anti-wear, anti-corrosive and anti-oxidant.additive.