Synthetic oil is as the name suggests not a naturally occurring compound, instead it is man made, consisting of chemical compounds which themselves have been artificially created (synthesized).
These synthetic lubricants can be made from modified petroleum components obtained from whole crude oil or manufactured using other raw materials. Synthetic oil is most often used as a substitute for mineral oils and lubricants when operating in extremes of temperature.
Synthetic oil provides superior mechanical and chemical properties than those found in basic mineral oils, this being vital in some areas, e.g. aircraft turbines. The high and extreme operating conditions found here require the use of synthetic oils. It is however interesting to note that piston driven aircraft engines for the most part can use mineral oils.
A bit of History
It was Dr. Hermann Zorn of I.G. Farben Industries in Germany who actually started the search for lubricants which had all the properties of natural mineral oils, but did not have the problems associated with gelling or gumming.
Altogether he produced over 3500 esters, these including diesters and polyolester in the 1930's to 1940's. Working at the same time in the USA Dr. W.A. Zisman was also synthesizing esters, concentrating on diesters.Synthetic Motor Oils
Chevron in the U.S.A are said to be the first to commercially use hydrocracking technology, this being expanded in the 1990's making Chevron (then) one of the world's largest manufacturers of API base oils.
Today these oils are marketed as fully synthetic motor oils. Later Chevron Phillips (as it was then) started the production of of polyolefin (PAO) Group IV base stocks, an improved form of automotive synthetic motor oil.
The base stocks for synthetic motor oils are:-
Semi synthetic motor oils (also known as 'synthetic blends') are based on mineral oils which have no more than 30% of synthezied oils present.
These are designed to have many of the benefits of synthetic oil, but without the high costs associated with pure (or fully) synthetic oil.
Some of these lubricants use much less than 30% of these synthezied elements, some high performance additive packs for motor oils, which consist of synthezied esters are also be considered as synthetic lubricants.
When choosing the right mineral, synthetic and fully synthetic oils for your application it is always best to ask the experts, and exol's experts are here to help you.