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.his is one reason synthetic oils last so much longer than non-synthetics. The physical property used to quantify an oil's resistance to viscosity change with temperature is known as the Viscosity Index (VI). The higher the VI, the more resistant to viscosity change the oil is.