Penn and ExxonMobil address long-standing mysteries behind anti-wear motor oil additive

The pistons in your car engine rub up against their cylinder walls thousands of times a minute; without lubrication in the form of motor oil, they and other parts of the engine would quickly wear away, causing engine failure. Motor oil contains chemical additives that extend how long engines can run without failure, but, despite decades of ubiquity, how such additives actually work to prevent this damage have remained a mystery.