“What is synthetic motor oil? AMSOIL synthetic lubricants are chemically engineered to form pure lubricants. They contain no contaminants or molecules that don’t serve a designed purpose. Because of the molecular structure of synthetic oil there is less friction on moving parts which increases fuel mileage.
Conventional lubricants, on the other hand, are refined from crude oil. Contaminating elements such as sulfur, nitrogen, oxygen and metal components such as nickel or vanadium are inherent to crude oil and cannot be completely removed through the refining process. Because of the chemical composition of Amsoil, their Signature Series Oils are designed to go 25,000 miles or one year between oil changes!”