A review on the properties and tribological performance of recent non-aqueous miscible lubricants

• Tribological performance of the non-aqueous miscible lubricants is reviewed. • Vegetable oils as a sustainable and environmentally friendly lubricant is explored. • Nanolubricants based on ionic liquids (ILs) are presented. • Nanolubricants for high-temperature applications. This review presents the literature review on the recent research on the tribological performance of non-water miscible lubricants. First, the paper reviewed the tribological properties of vegetable oil, blend oil, synthetic oil and ionic liquid. Aside from that, the tribological performance of lubricants with ionic liquids (ILs) and nanoparticles is being studied. According to the findings, more research should be conducted into oil-miscible ILs for mineral, vegetable oils and nanolubricant. The review has also explained the dispersion stability, viscosity and viscosity index, thermal conductivity, thermal-oxidative stability and tribological performance of nanolubricant. Finally, future recommendations on lubricant research are also discussed.