In 1999 the BBB's NAD, in a non-binding non-legal decision related to advertising standards, decided that C
Today about the only conclusion you can draw from a synthetic label is that the oil most likely has a more stable base oil blend than one not labeled synthetic, assuming the marketer is ethical. A more stable base oil is only part of an oil's performance characteristics as the additives dominate in many performance attributes. If you really want to define an oil's performance, look to the industry and OEM approvals it has. These take into account both the base oil and the additives, and at least they are defined and regulated. The term "synthetic" is not.