The main thing is I am just looking for a reasonably priced motor oil that will protect my engine well, keep the engine clean (maybe with help from Auto-RX), and will flow good at fairly low temeratures in the wintertime (say -10 F). In the summertime I need an oil that will flow quickly enough to protect a double overhead cam engine but protect well in 100+ F temperatures.
I am not convinced that any conventional motor oil flows all that good in the cold, although some do better then others and the Quaker State Winter Blend is interesting. I don't know about blends but it seems that they would flow somewhat better then the conventional motor oils.
From what I have found out some far about the Mobil Drive Clean Plus motor oils, there is apparently good evidence they keep engines clean and reduce wear. The 10W30 Drive Clean Plus is a somewhat thicker 10W30 that would probably protect good at high temperatures, but I would have to make sure that it flows quickly enough. And these oils are blends with some synthetic and I figure Mobil has had over thirty years to work on synthetic oils.