I know this has been hashed to death on the site, but a recent article in Lubes'n'Greases Magazine does an excellent job describing what is a synthetic, suggests what should define a synthetic blend, and gives a brief history of how it's been discussed at high level industry groups.
Read the full article from Steve Swedberg
Originally Posted By: From the Article
It's well accepted that synthetic lubricants may include Group III base stockes made via hydroisomerized refining techniques, the new gas-to-liquids base stocks made from the Fischer-Tropsch process, as well as the arsenal of chemically synthesized products listed in the SAE J357-FEB95. That leaves individual oil marketers to grapple with how to define the synthetic oil lines they offer. For synthetic blends, should they decide on a 30 percent minimum content or something else? Could it be that someone out there will decide - or already has - that just a little bit is enough? For full synthetics, the question is whether using highly dilute additives results in a legitimate product. Will blenders play it fast and loose? Maybe Sir Walter Scott had it right when he said, "Oh! What a tangled web we weave when firs we practice to deceive!"