By definition, true synthetic oils are formulated from small molecules subjected to a chemical reaction. Perhaps the oldest process is known as the “Fischer-Tropsch process” that converts carbon dioxide, carbon monoxide and methane into liquid hydrocarbons. This was, in fact, the process originally developed and used by the Germans during World War II to supplement limited supplies of crude oil.
By taking the short chain hydrocarbons thus synthetically created, and polymerizing them into longer single chain hydrocarbons, synthetic oils with controllable performance characteristics can be created.
While it is easy to focus on synthetic forms of petroleum oils, we would be remiss in not including other forms of synthetics wherein the hydrogen (as in hydrocarbon) is replaced with fluorine (as in fluorocarbon) to produce a synthetic oil most commonly used in vacuum pumps. These fluorocarbon oils (e.g. DuPont Krytox) are exceptionally stable with very low vapor pressures making them ideal for high temperature and low pressure applications such as in aerospace.
