lubricating oil additives are chemical compounds that are mixed with lubricant base oils to improve their performance. They are formulated into packages for specific lubricant bases and end-use applications. The market for lubricant additives is driven by global demand for automotive lubricants (heavy-duty, passenger car motor oils and metalworking fluids), industrial lubricants (metalworking and hydraulic fluids) and a range of consumer applications. The addition of lubricant additives increases the life and production of final lubricants and reduces maintenance costs.

The major functional lubricant additives are dispersants, detergents, oxidation inhibitors, antiwear agents and extreme-pressure additives. These are complemented by abrasive and demulsifying agents, viscosity index enhancers and pour point modifiers.

Defoamants prevent foaming in lubricants which disrupts the flow of oil and cooling of parts, leading to a reduction in load carrying capacity and a decrease in lubricant efficiency. Pour point depressants are used to lower the freezing point of mineral oil lubricants; they act by adding large, negatively charged hydrophilic molecules to the surface of the molecule which reduces the intermolecular interactions and allows the molecule to form closer contacts with metal surfaces.

Grease additives such as calcium sulfonate greases, polyurea greases and aluminum complex greases are characterized by low pour points, good rheological properties, high temperature service capability and water tolerance. Other important grease additives include lubricity modifiers, thickeners and tackifiers. Odorants and dyes are added to lubricants and greases to ensure that the products have an acceptable scent and appearance. In the past some mass-marketed lubricant additives such as those containing PTFE/Teflon caused a backlash among consumers and were condemned by U.S. federal regulators.