It has always been my "gut" feeling that conventional group one or two oils had some type of redeeming quality which allows them perform well inside the bowels of our engines. I have always been impressed how some group one and two oils perform pretty decently in comparison to much more expensive synthetics , at least in short term drain intervals. Thus I always thought of blended oils as being the "best of both worlds", thinking that conventional oil has its benefits, as does synthetic oil. I am just talking off the top of my head here, based on my gut feelings, nothing scientific to prove any of my beliefs. Lately I have been looking at the Schaeffers and Synergyn products (I am in the process of using both of them in my next two oil changes). I noticed that they both talk about the superior lubricity qualities of conventional oil stocks. From their literature it sounds as if they use conventional oils due to their lubricity traits. So the question is, does conventional oil have superior lubricity traits compared to synthetic oil ?. In other words, is there something about group one and two oils that is helpful to the operation of our engines, which you don't quite get with a full synthetic oil ?. I hope I am not confusing things here. As usual, any opinions welcomed.