Synthetic oils were invented in the 1930s. It was not until the 1970s, however, that synthetic oil began to be widely used. Synthetic oil can be made in three ways. One type of synthetic oil actually is regular crude oil with added ingredients. The other two types are created by mixing chemicals and ingredients found in crude oil. Oil is divided into five categories, based on ingredients and use. The first two groups are completely natural, but the other three groups contain some types of synthetic ingredients.
Group III oil is not strictly a synthetic oil. It is made from crude oil, with some additives. However, Group III oils generally are classified as synthetic because they are processed with the added ingredients. The base stock of Group III oils comes from crude oil. The oil is refined much more than oil Groups I or II. Ingredients found in group three oils contain: mineral oil and alpha-olefins. Alpha-olefins are added for extra viscosity, so the oil can be used in colder temperatures. Alpha-olefins also make the oil more slippery, which is useful for a variety of tasks. Group III oils are used in gasoline- and diesel-powered engines. According to Synthetic Oil Technology, Group III oils can be mixed with group I or Group II oils with no problems.
Group IV oils are true synthetic oils. These oils are made with polyalpha-olefins, and they also are known as PAO oils. These oils are produced by synthesizing all the chemicals and ingredients found in traditional crude oil. According to TheOilDrum.com, a series of hydrocarbons typically make up crude oil--including, but not limited to, residuum, naphtha, kerosene, sulfur, paraffin, nitrogen and vanadium. Group IV oils also contain more additives to make the oil stronger and to add viscosity to the oil. Castrol Oil Company states some of these additives include alpha-olefins to make it slippery, anti-wear ingredients to make it last longer than natural oil, anti-oxidants to make it better for the environment and detergents to help mix it together. PAO oils usually are made from a series of hydrocarbon molecules. Group IV oils typically are used for motor oil after engine use has reached at least 5,000 miles of driving.
Ester-based oils make up the Group V synthetic oils. These oils are not as well-used as the PAO oils. The main difference between ester-based oils and PAO oils is the ingredient used to give the oil viscosity. According to Castrol, ester oils use ester molecule chains derived from organic acids to create a fat-like or oil-like substance. The ester is used to bind the other ingredients in the oil together. Ester oils contain many of the same ingredients PAO synthetic oils contain. Ester oils typically are used for mechanical applications but also are used as engine oil in extreme hot or cold conditions.
