Valvoline stands behind the product...
Here's my story;
I always use Valvoline mainly cause it's recommended and it's handy at the Cummins store along with all the required filters. But, just this past Dec while on my way to Roswell NM. I passed through a town called Monticello in Utah and decided to pick up some oil for a change out in Roswell, at the local NAPA. When we went to do the change , in Roswell at the QuickLube, we opened the 3 jugs and poured the first one in as normal but the other 2 were all lumpy and crystallized, is the only way I could describe them. The fellow changing the oil said he'd never see it like this before and refused to put it in the engine. Any way long story short (a bit) I just called Valvoline after getting back home and they arranged for me to p/u 3 fresh jugs at the local NAPA here in town.
I have to say really impressed with service. No run around at all I made one call and that was it.