Synthetic oil is oil consisting of
chemical compounds which were not originally present in
crude oil (
petroleum) but were
artificially made (
synthesized) from other compounds. Synthetic oil could be made to be a substitute for petroleum or specially made to be a substitute for a
lubricant oil such as conventional (or mineral)
motor oil refined from petroleum. When a synthetic oil or
synthetic fuel is made as a substitute for petroleum, it is generally produced because of a shortage of petroleum or because petroleum is too expensive. When synthetic oil is made as a substitute for lubricant refined from petroleum, it is generally to provide superior mechanical and chemical properties than those found in traditional mineral oils.