Development of Engine Oil Deterioration Monitoring System Using Estimation Method of Oxidation Induction Time

The research discussed in this paper revealed a strong correlation between the anti-oxidation performance of engine oils and sludge production. The results of NOx bubbling tests and engine bench tests showed that the main factors in the deterioration of anti-oxidation performance are heat, air, NOx, and unburnt fuel. Detailed analysis indicated that the rate of deterioration of anti-oxidation performance could be expressed as formulas. The use of these deterioration rate formulas to calculate the deterioration in anti-oxidation performance in a real engine showed that the formulas could be employed in a monitoring system. The use of these estimation methods of oil anti-oxidation performance by the engine control unit (ECU) would enable onboard estimation of oil deterioration.