Motor oil degradation during urban cycle road tests

Abstract

Several civilian vehicles in China operate in urban traffic conditions and have their motor oil changed every 5,000 km. This study investigates the variations in oil properties after servicing at 5,000 km, based on systematic road tests (including a repeated test, a parallel test, and a new vehicle test). The physicochemical properties, changes in components, oxidation stability, detergent-dispersant performance, and tribological properties of motor oils were analyzed. The results showed that the total acid number (TAN) of oils increased with the operation mileage, by up to 1.41 mgKOH/g. The total base number (TBN) decreased after the road tests were completed, and the decrease was less than 44.6%. The kinematic viscosity (KV) of most oils decreased initially and then stabilized in the middle stage, before starting to increase later in the experiment. The change in KV at 100 ℃ was less than 15.96%. The oxidation onset temperature (OOT) of the oils diminished gradually with the operation mileage. All OOT values of the used oils were higher than 210 ℃. A spot test indicated that the used oils retained their detergentdispersant performance to an appropriate extent. The four-ball wear scar diameters and friction coefficient of the used oils did not increase significantly after the road tests were completed. This study can serve as a reference for end-users when changing motor oils.

Impregnation of Wood with Waste Engine Oil to Increase Water- and Bio-Resistance

“…In the spectrum of treated and untreated wood, the absorption band at 1030 cm −1 is characteristic of symmetric stretching of C-O-C dialkyl ethers, as well as deformation of CH bonds and β-O-4 bonds in lignin [39]. During the operation of the internal combustion engine, engine oils are exposed to high temperatures and pressure, contact with oxygen and various metals, and as a result, oil hydrocarbons undergo oxidation, condensation and decomposition processes [54]. In the composition of spent motor oils, absorption bands were found at a frequency of 720 cm −1 and 1150 cm −1 , which correspond to the valence vibrations of the peroxide group (-C-O-O-) with increased chemical activity [55].…”

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

“…Due to the mixing of oil with air and hot flue gases, ideal conditions are created in the crankcase for oxidation as well as nitration. On the same principle, the authors [30,54] presented the formation of sulfates, i.e., the formation of SO x reactions from flue gases with oil. However, given the maximum concentration of 10 ppm sulfur in the fuel, this seems unlikely [56].…”

“…Understanding the degradation processes that occur in motor oil in operation is important with respect to meeting current and future requirements. Researchers are also studying motor oil degradation with a view to optimizing the replacement intervals [29][30][31] and setting up the maintenance systems [32][33][34][35].…”

Sludge Formation Analysis in Hydraulic Oil of Load Haul Dumper 811MK V Machine Running at Elevated Temperatures for Bioenergy Applications

“…is test measures the concentration of acid in the oil. Quantity of potassium hydroxide is required for neutralizing the acid inside the oil sample, and measuring the weight, in milligram KOH per gram of oil [29,30]. It measures oxidation stability at elevated temperature (Figure 12).…”