Aarav Patel
Independent Researcher
India
ABSTRACT
Tribological performance of engine oils is critical to the reliability, efficiency, and longevity of internal combustion engines. This manuscript presents a comprehensive evaluation of five commercially available engine oils, encompassing mineral, semi-synthetic, and fully synthetic formulations prevalent up to 2018. Wear scar diameter, coefficient of friction, and film thickness under boundary and mixed lubrication regimes were systematically measured using a ball-on-disk tribometer. Statistical analysis of the resulting data reveals significant differences in wear and friction behavior correlated with base oil type and additive package. Key findings demonstrate that fully synthetic oils exhibit the lowest wear scar diameters (average 0.45 mm) and coefficients of friction (0.07), whereas mineral oils show higher wear values (average 0.62 mm) and friction (0.12). Research gaps are identified in understanding the long-term degradation mechanisms of ester-based synthetics under soot-loaded conditions. Conclusions emphasize the selection of oil formulation tailored to operating conditions to optimize engine durability and fuel economy.
KEYWORDS
Tribology, engine oils, wear scar, coefficient of friction, boundary lubrication
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