Dilution of engine oil with unburned fuels alters its lubricity and tribological properties. In this research paper, SAE-40 lubricating oil samples were contaminated with known percentages (5%) of fuels (diesel, palm-sesame biodiesel blend (B30), B30 + ethanol, B30 + dimethyl carbonate, B30 + carbon nanotubes and, B30 + titanium oxide). The effect of all these fuels on wear and frictional characteristics of lubricating oil was determined by using a 4-ball tribo tester and wear types on worn surfaces were analyzed by using SEM. Lubricating oil diluted with B10 (commercial diesel) showed highest COF (42.95%) with severe abrasive and adhesive wear than mineral lubricant among other fuels. Lubricating oil diluted with palm-sesame biodiesel (B30 blend) with alcoholic additives showed comparatively less COF, less wear scar diameter and polishing wear due to presence of ester molecules. Lub + B30 + Eth exhibited increment in COF value (35.81%) compared to SAE-40 mineral lubricant. While lubricating oil contaminated with B30 with nanoparticles showed least frictional characteristics with abrasive wear. Lub + B30 + TiO₂ showed least increment in COF value (13.78%) among all other contaminated fuels compared to SAE-40 mineral lubricant. It is concluded that nanoparticles in biodiesel blends (B30) helps in reducing degradation of lubricants than alcoholic fuel additives and commercial diesel.

用未燃烧的燃料稀释机油会改变其润滑性和摩擦学性能。在这篇研究论文中，SAE-40润滑油样品被已知百分比（5％）的燃料（柴油，棕榈芝麻生物柴油混合物（B30），B30 +乙醇，B30 +碳酸二甲酯，B30 +碳纳米管和B30）污染+氧化钛）。所有这些燃料对润滑油的磨损和摩擦特性的影响均通过四球摩擦试验仪测定，并通过SEM分析了磨损表面上的磨损类型。与其他燃料相比，用B10（商业柴油）稀释的润滑油显示出最高的COF（42.95％），且具有严重的磨蚀性和粘附磨损。用棕榈芝麻生物柴油（B30混合物）和酒精添加剂稀释的润滑油显示出相对较低的COF，由于存在酯分子，因此减少了磨损痕迹直径和抛光磨损。与SAE-40矿物润滑剂相比，Lub + B30 + Eth的COF值增加了（35.81％）。而被纳米颗粒B30污染的润滑油显示出最小的摩擦特性和磨料磨损。润滑油+ B30 +钛₂表明至少增量相比SAE-40矿物润滑剂所有其它杂质的燃料中COF值（13.78％）。结论是，与酒精燃料添加剂和商用柴油相比，生物柴油混合物（B30）中的纳米颗粒有助于减少润滑剂的降解。