For many years now, 5-20s in most-all labels were / are blends. But the synblend labels in 5w-20 (for instance Durablend) I'm guessing contains additional amounts / percentages of synthetic.
Now that 5w-30 has incorporated synthetic, I suppose Durablend 5w-30 can still coexist on store shelves, having more synthetic inside that jug than the white bottle Valv. 5w-30.
I wish there was regulations / legislations where the bottlers had to make-public the amount of synthetic in every synthetic blend bottle. In the meantime, it just makes sense that the amount of synthetic in Durablend 5w-30 will be greater than the new white bottle Valvoline in 5w-30.
These companies are adding synthetic to conventional oils to meet specifications / controls / ratings/. The specs are probably getting tougher to meet. So now 5w-30 will contain varying amounts of synthetic, depending on the bottler label / brand.
You hit the nail on the head Triple_Se7en! When I posted here, I also emailed Valvoline and they answered immediately which is impressive in its own right. They said that in order to achieve a 5W weight, it is almost a requirement to have some synthetic properties. The other reason is that more and more auto manufacturers are stating in the owner's manual that a synblend oil should be used so now the consumer can feel comfortable using VWB. He did also say that VWB has nowhere near the percentage of synthetic that MaxLife has which is slightly more than 30%. He also confirmed that WB does not have enough to allow for dexos certification.
