Two statements concerning synthetic oils follow. I am not a proponent of either of these positions; these are strictly for the purposes of discussion. Extended drains are not taken into consideration here. 1. Synthetic oils are no better than conventional oils (aka dino) except in extreme conditions that are truely corner cases for the average driver. Most UOAs show no real difference between synthetic and dino, leading one to believe that synthetics aren't superior to dino at effectively lubricating an engine under most conditions. 2. ConocoPhillips SM oils are synthetic blends, with some suggesting that they may contain as much as 50% GPIII synthetic. I have even heard some say that CP "had" to go to a synthetic blend to get their oils to meet SM specifications. That seems extreme, but it is interesting that CP went to a synthetic blend for their SM oil. CP isn't a bunch of dummies, so there must have been a good reason for them to use a synthetic blend in order to certify to SM specs. So, why would CP change to a synthetic blend for their SM oils if there is no benefit to synthetic oil? Is it simply that under real world driving conditions synthetic has no advantage, but for the purposes of meeting the SM standard in the laboratory the synthetic offers attractive properties? By the way, I use both so I consider myself fairly neutral here.