You could try to mix the 5w20 with some Valvoline Synpower 5w40 for a synthetic blend.
In that way you would use up the 5w20 for a longer OCI and not risk the wear problems associated with the VWB 5w20 and it's very weak add pack. Just a suggestion....that's what I would do if I was sitting on a stash of weak oil.
Just mix the VWB with the Valvoline Synthetic Synpower in a 50/50 proportion. Same Family of Oils and SynPower, although not overpowering, should compliment the Dino and give you a nice blend.