Using up some old stock, I have three Valvoline 20w50. I poured each, one at a time, into a clear jug for inspection. All had a identical green hue to them, and I'm not sure if that's the formula of if they have gone bad, so I noted that and set them aside for further inspection. I can snap some pictures of the bottle and the oil tomorrow in the daylight but just curious if anyone is immediately familiar with this as maybe an older heavy oil weight Valvoline formula? These were likely garage sale purchases at least a decade ago, oil is probably 10-20 years old. I recall it was conventional. Like I said, pics if needed but just posting this while I'm remembering it. Thanks.