Agocs, A.; Nagy, A.L.; Ristic, A.; Tabakov, Z.M.; Raffai, P.; Besser, C.; Frauscher, M. Oil Degradation Patterns in Diesel and Petrol Engines Observed in the Field—An Approach Applying Mass Spectrometry. Lubricants2023, 11, 404.
Agocs, A.; Nagy, A.L.; Ristic, A.; Tabakov, Z.M.; Raffai, P.; Besser, C.; Frauscher, M. Oil Degradation Patterns in Diesel and Petrol Engines Observed in the Field—An Approach Applying Mass Spectrometry. Lubricants 2023, 11, 404.
Agocs, A.; Nagy, A.L.; Ristic, A.; Tabakov, Z.M.; Raffai, P.; Besser, C.; Frauscher, M. Oil Degradation Patterns in Diesel and Petrol Engines Observed in the Field—An Approach Applying Mass Spectrometry. Lubricants2023, 11, 404.
Agocs, A.; Nagy, A.L.; Ristic, A.; Tabakov, Z.M.; Raffai, P.; Besser, C.; Frauscher, M. Oil Degradation Patterns in Diesel and Petrol Engines Observed in the Field—An Approach Applying Mass Spectrometry. Lubricants 2023, 11, 404.
Abstract
Engine oil degradation and tribological properties are strongly interrelated. Hence, understanding the chemical processes resulting in additive depletion and degradation products is necessary. In this study, in-service engine oils from petrol and diesel vehicles were analyzed with conventional and advanced methods (mass spectrometry). Additionally, the effect of the utilization profile (short- vs. long-range) was studied. Petrol engine oils generally showed accelerated antioxidant and antiwear degradation and higher oxidation, especially in case of a short-range utilization profile, which can be attributed to the higher air-to-fuel ratio (more rich combustion) compared to diesel engines. A detailed overview of oxidation and nitration products, as well as degradation products resulting from zinc dialkyl dithiophosphate and boron ester antiwear additives, diphenylamine antioxidants and salicylate detergents is given. A side-reaction between oxidation products (aromatic carboxylic acids) and the boron ester antiwear is highlighted. This reaction was only detected in the petrol engine oils, where the oxidation products were measured in a high abundance. However, no side reaction was found in the samples from the diesel vehicle, since there the aromatic carboxylic acids were largely absent due to lower oxidation.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.