Originally Posted By: Tom NJ
Synthetic chemicals are defined by the final processing steps, not the origin of matter from billions of years ago.
In chemistry, a synthetic molecule is made by reacting two or more smaller molecules, elements, or radicals to create a new larger and more complex molecule.
In lubricants, synthetic is a marketing term implying higher performance through the exclusive use Group III, Group IV and/or selected Group V base oils. Group III base oils do not technically meet the chemistry definition of synthetic, however, since 90+% of its molecules were created new by man by altering or rearranging mineral oil molecules, many feel the term synthetic does applies. Others apply it by place more emphasis on the base oil performance properties than on how it was made.
There are some motor oils that claim to use only "true" synthetic base oils, but there is no reason to believe these oils will perform better due to these base oils, as the additive system plays a greater role in the finished oil performance. You can be sure, however, that they will be more expensive.
All definitions of "synthetic" lubricants are based on the
base oil content only, exclusive of additives or small amounts of diluent oil.
While this may be academically interesting, none of it really matters when selecting a motor oil. You only need to be concerned with the specifications and approvals the oil has, and the reputation of the oil manufacturer making such claims.
Very well stated Tom