Comparing oil condition in diesel and gasoline engines

Purpose This paper aims to compare the conditions of in-service oils from diesel and gasoline engines, with focus on nitration. Design/methodology/approach Oil conditions of seven engine oil samples from five diesel-fueled vehicles and nine oil samples from eight gasoline-fueled vehicles with total mileage ranging from 13,600 to 30,000 km were determined via Fourier-transform infrared spectroscopy as well as neutralization number (NN) and total base number titration. Findings Chemical deterioration was characterized by significant differences in oxidation, nitration, NN increase and residual aminic antioxidant contents. Originality/value Uncovering differences in the oil degradation of oils from gasoline and diesel engines enables improved condition-based maintenance strategies and the prediction of oil condition dependent tribological performance.