Study of the Effect of Physicochemical Degradation and Contamination of Motor Oils on Their Lubricity

Internal combustion engine lubrication is essential for unwanted energy and material losses. As part of the experimental work, lubricity both new worn motor oils Society Automotive Engineers (SAE) 15W-40 SAE 10W-40 with different American Petroleum Institute (API) performance classifications, which were taken from various trains during maintenance or oil change, was assessed. A total sixteen lubricant samples evaluated. Lubricity, i.e., load capacity lubricating film, evaluated on basis Reichert test. Viscosity, as one most important parameters lubricants, by Stabinger Viscometer. Chemical degradation (oxidation, nitration, sulfation), contamination fuel, soot, water, loss antioxidant zinc dialkyldithiophosphate (ZDDP) monitored Fourier-transform infrared (FTIR) spectroscopy. Of fresh oils, OMV API SL/CF had best lubricity. URANIA LD CI-4 M7ADS V CH-4/SL showed similar III CF-4/SG highest wear surface, lowest lubricity, tested oils. Correlation analysis data confirmed that fuel content penetrated significantly negatively correlates viscosity (R = ?0.87). The low water in does not cause a significant negative effect correlation between oxidation, sulfation products chemical ? 0.90). These improve due to their polarity, they have caused better compared Even depletion ZDDP did affect reduction anti-abrasion properties chemically degraded results testing current excellent maintain throughout life.