Welcome to Synthetic-Oil-Technology.info! This site is dedicated to giving you some basic facts about synthetic motor oils and other lubricants commonly used in today's cars and trucks.
The easiest way to define what synthetic oil is, is to define what it is NOT. Conventional motor oil as we have known it for the last 100 years or so is derived from crude oil that is taken from the earth with oil wells. Through a complex distillation process the crude oil is refined into many different liquids, or fractions, each having distinct characteristics. Some are very light and are used as fuel (gasoline, kerosene, diesel fuel), and some are heavier and are used as lubricants (motor oil, gear lube, grease). There are many molecular compounds present in crude oil and many of those compounds are still present in the refined product, detracting from the physical properties of that product. For instance, paraffinnic waxes are present in crude-based oil, but contribute nothing to the lubricative properties of the oil. Also, the size of the hydrocarbon molecules themselves are non-uniform in crude-based oils. Synthetic oil contains none of these contaminants and the hydrocarbon molecules are very uniform, giving the synthetic oil base better mechanical properties at extreme high and low temperature (see the sections below on physical properties). By contrast, synthetic oil is not distilled from crude oil. It is made through a chemical process known as the Fischer-Tropsch process, starting with raw materials like methane, carbon monoxide, and carbon dioxide. This process was developed by Germany in WWII, when that country's access to crude oil was very limited.
Motor oils are derived from base stocks. That is, a generic oil base is modified with additives to produce a lubricant with the desired properties. A base stock oil with no additives would not perform very well at all. Base stocks are classified by the American Petroleum Institute (API) and fall into one of five categories.