This can and does happen. Though, for most items, the net gain you'll realize probably isn't worth the effort. Consider this from Walmart [1]. Mobile 1 5W-30

This can and does happen. Though, for most items, the net gain you'll realize probably isn't worth the effort. Consider this from Walmart [1]. Mobile 1 5W-30. Something I buy frequently, but not from walmart. Walmart's site doesn't list a SKU, but you can see the UPC code from one of the pictures. Same exact SKU as Advance Auto [2]. The problem? I know for absolute fact that the containers that hold the oil look totally different (and Walmart's online photo does not reflect reality). I don't buy motor oil from Walmart because this is the crap they pull. And it's not like this just recently happened or the manufacturer recently switched. I've compared the containers across years and several states now. Maybe the packaging is just different but it really is the same oil on the inside. I don't trust Walmart enough to find out. 1: https://www.walmart.com/ip/Mobil-1-Advanced-Full-Synthetic-Motor-Oil-5W-30-5-Quart/17034372 https://www.walmart.com/ip/Mobil-1-Advanced-Full-Synthetic-M... 2: https://shop.advanceautoparts.com/p/mobil1-advanced-5w-30-full-synthetic-motor-oil-5-quart-jug-44899/10069908-P?searchTerm=mobile%201%205w-30 https://shop.advanceautoparts.com/p/mobil1-advanced-5w-30-fu...