Are all additives used in engine oil the same?

There are many different types of additives that perform different functions. Below are some of the different performance additives and the imparting properties they provide to a finished lubricant.
– Antioxidants are used to extend the operating life of an oil by increasing oxidative resistance of the base oil.
– Corrosion inhibitors are used to neutralize acids by forming a chemical barrier to repel moisture from metal surfaces.
– Anti-wear/extreme pressure agents protect machine parts from wear and loss of metal during boundary lubrication. Zinc Dialkyldithiophosphate, simply known as ZDDP is a popular example and is used in many different automotive and industrial applications.
– Detergents/Dispersants are used to keep machine internals clean and free of deposits while also suspending contamination until the oil can be changed.
– Anti-foam agents are chemical compounds which are used to weaken the oil bubbling wall and allowing foam bubbles to burst more readily.
– Friction modifiers are used to alter the friction between moving parts.
– Pour Point Depressants (PPDs) are used to reduce the formation of wax-crystals in an oil at low-temperatures.
– Viscosity Index Improvers (viscosity modifiers) are used in the product of multi-viscosity lubricants. These large polymer additives increase the viscosity of a fluid throughout its useful temperature range.