Engine oil additives minimize engine wear by providing a protective chemical coating between an engine's movable parts. A common anti-wear additive used in the automotive industry is called zinc dialkyldithiophosphate, or ZDDP.
Motor oils typically contain performance chemical additives to provide added protection, enhance the efficiency and prolong the service life of motor engines. The ZDDP additive lessens damage to the pistons that constantly grind against their cylinder walls at tremendous speeds.
As of 2015, a detailed account regarding the exact mechanism of how ZDDP works is still lacking. However, improvements in nanotechnology helped determine that ZDDP is converted into a "tribofilm" that coats and sticks to the metal surfaces of the engine to reduce wear, based on a study conducted by researchers from the University of Pennsylvania and ExxonMobil. The mechanism is said to occur at the atomic level.