What is Oil Oxidation?
Over time, oil tends to break down by reacting with dissolved atmospheric oxygen. This oxidation starts a chain reaction that first forms hydro peroxides and then progresses to other oxidation products – all of which increase acidity and viscosity, darken colour, and leave surface deposits and varnish. By eliminating the initial hydro peroxides and by interrupting the chain sequence, oxidation-inhibiting additives slow this deterioration rate by more than a hundredfold. Useful life continues through an induction period as the oxidation inhibitor supply is slowly depleted. Deterioration rate depends strongly on temperature. Although adding an inhibitor delays life-ending breakdown, slow accumulation of oxidation products and contaminants such as wear particles and soot in engine oils eventually signal a need for an oil change. The good news is that life expectancy is extended with the paraffinic structure of new hydrocracked Group II and Group III oils. Absence of aromatic hydrocarbons
