Lubricant Base Oils: Analysis and Characterization of

Abstract Lubricant base oils, or base stocks, are hydrocarbon lubricant components which are combined with performance additives to make finished industrial and automotive lubricants. A lubricant is a substance that reduces friction and wear between surfaces. Base oils typically comprise 80–99% of the finished lubricant. They are refined from selected crude oils, re‐refined from used oil, synthesized from specific organic compounds, or extracted from renewable resources, such as seed oils. Base oils formulated into finished lubricants help to reduce friction and wear between moving surfaces, remove heat, seal, cushion against shock loads, and remove abrasives and contaminants from the lubricated area. Base oil analysis and characterization is important for understanding how the physical and chemical properties of these materials relate to performance in finished lubricants. It is also essential for maintaining quality control (QC) over the manufacturing process, for quality assurance (QA) of the finished product, and for setting specifications between buyer and seller.