Editing Lubricant (section)

=== Reduce friction ===
Typically the lubricant-to-surface [[friction]] is much less than surface-to-surface friction in a system without any lubrication. Thus use of a lubricant reduces the overall system friction. Reduced friction has the benefit of reducing heat generation and reduced formation of wear particles as well as improved efficiency. Lubricants may contain [[Chemical polarity|polar]] [[oil additive|additives]] known as friction modifiers that chemically bind to metal surfaces to reduce surface friction even when there is insufficient bulk lubricant present for hydrodynamic lubrication, e.g. protecting the [[Valvetrain|valve train]] in a car engine at startup. The base oil itself might also be polar in nature and as a result inherently able to bind to metal surfaces, as with [[polyolester]] oils.