I am not sure I have any logical thought process here, but, I was thinking about synthetic blend motor oils. I think for their two blends, Durablend and MaxLife blend, Valvoline advertises 70% GP II and 30% GP III. That kind of makes sense as GP II and GP III are closely related. But I am thinking it is still a blend, not a compound. The GP II still has its own "character" and GP III still has its own "character." If I assume or just make up a situation, I will say the GP II molecules will "wear out" at (X) miles/hours/use. The GP III molecules will "wear out" at (X+) miles/hours/use. In the SynBlend, would the GP III molecules carry an amount of the "load" that GP II molecules now do not have to carry so the total blend called synthetic blend lasts longer than just conventional? What about heat? The GP II molecules are going to react to heat the same way. How is the heat carrying range, the safe operating temperature of the blend increased? I am not speaking of VI here as surely the GP III would increase the VI. What about add packs? Are there differences in add packs between GP II only and GP II/III blends? Is it a "higher quality" add pack, or, just the same. Is it less than the add pack for a total GP III? I am thinking the same principles would apply to a GP II/GP IV blend. I can't help but think a blend is a much better deal dollar wise. With 5 quart jugs at Wal Mart, the difference between a conventional and a blend is on the order of just one dollar. The difference between a conventional and a "full synthetic" is on the order of 8 dollars. To me, just my practice, the synthetic would be well worth the 8 dollar difference. If the blend is really any better, it would not be wise to not pay just an extra 20 cents a quart for the blend. An example, Valvoline MaxLife blend is only $1.00 a jug more than their Premium conventional. I think that is a fantastic deal. Also,it could be that it is just very late at night and I am thinking, sort of, maybe .