The experiments encompassed different ratios of nanometal oxides and temperatures ranging from 27 to 71 \({}^{\circ}\)C, with oil viscosities of 77 and 350 Pa\(\cdot\)s. The results demonstrated that these factors influenced the viscosity of the oil mixture, resulting in a reduction of 50-70% depending on the ratio of nanometal oxide used [16]. [PERSON] suggested that the viscosity of the heavy oil mixture could decrease by 20-93% depending on the ratio of the emulsion solution blended into the lubricating oil [17]. In a study by [PERSON] et al. in 2014, the authors demonstrated that the decrease in viscosity depends on the density and size of metal particles [18]. According to [PERSON] et al., SiO\({}_{2}\) nanoparticles can exhibit a micro-bearing effect as rolling elements at the friction interface, leading to friction reduction [19]. [PERSON] et al. have developed an eco-friendly oil with improved lubricity by adding SiO\({}_{2}\) nanoparticles to epoxidized Madhuca indica oil [20]. This addition resulted in improved thermo-physical properties and tribological performance, including a reduction in the coefficient of friction and wear rate up to a concentration of 0.8 wt% nanoparticles. [PERSON] et al. conducted a study to investigate the utilization of hard-shelled soft-core composite nanoparticles as a novel additive in grease [21]. Incorporating 1 wt% of these nanoparticles led to a notable decrease in the coefficient of friction and wear scar diameter, creating a composite lubricating film with solid-liquid phases and enhancing the tribological characteristics of conventional greases. [PERSON] et al. conducted a comparative study on the tribological properties of chemically modified rapeseed oil using two different anti-wear nano additives, namely TiO\({}_{2}\) and Al\({}_{2}\)O\({}_{3}\)[22]. By employing a pin-on-disc tribometer, [PERSON] et al. observed that the chemically modified rapeseed oil containing spherical TiO\({}_{2}\) nanoparticles displayed a smoother worn pin surface and a lower friction coefficient in comparison to the oil with fibrous nano Al\({}_{2}\)O\({}_{3}\) wire. [PERSON]. [PERSON] et al. conducted a study to investigate the effectiveness of adding ZnO to rapeseed oil at various concentrations using a four-ball machine. [23]. They observed that adding 1 wt% ZnO did not improve the friction coefficient but reduced the wear rate compared to neat rapeseed oil. The researchers formulated a novel lubricant by incorporating a dispersant (2-methoxyphenol) at a 1:1 ratio to the additive. They then examined the tribological performance of the lubricant based on the obtained results. [PERSON] and colleagues conducted a study to assess the influence of calcium carbonate (CaCO\({}_{3}\)) and silica (SiO\({}_{2}\)) nanoparticles on the physical, tribological, and rheological properties of lithium-based grease [24]. The research conducted by [PERSON] and colleagues demonstrated that the incorporation of calcium carbonate (CaCO\({}_{3}\)) and silica (SiO\({}_{2}\)) nanoparticles into lithium-based grease resulted in enhanced physical, tribological, and rheological properties compared to lithium-based grease. The authors determined that the optimal concentration of calcium carbonate in the lithium-based grease was found to be 1 wt%. At this concentration, the grease exhibited reduced friction and wear, improved resistance to water washing, increased thermal stability, and enhanced tribological behavior. In a study, [PERSON] et al. utilized either TiO\({}_{2}\) or SiO\({}_{2}\) nanoparticles in a cooling lubricant emulsion to address several tribological challenges. The inclusion of these nanoparticles resulted in a significant reduction in the friction coefficient, minimizing wear on the cutting tool, and reducing the variance of measured values, resulting in increased durability during the machining process [25]. The addition of SiO\({}_{2}\) and TiO\({}_{2}\) nanoparticles also resulted in reduced wear without any signs of chipping, cracking, or peeling of the coating.