Wal-Mart appeals to me b/c it's practically one-stop. It's much easier to grab oil or filters when your in the middle of picking up everything else than it is to make special trips. That being said, probably 70-80% of my stashed oil did NOT come from Wal-Mart, rather it was from sales and clearances elsewhere. But I find myself in a situation where almost all of my stash oils are heavier than I need for my vehicles now, so I've pretty much bought new oil for most of my oil changes since Feb. In light of the guilt I feel over buying MORE oil when I already have so much, picking up a $12 5 qt jug of dino at Wal-Mart eases my mind a tad.