I saw that Family, Farm and Home (just like a Tractor Supply) was having a sale on 5-qt. jug Mobil 1 full synthetic oil for $19.97 in the flyer. When I get there the jug doesn't look that same but they also have the jugs that look the same for $34.99. I have never saw this before and wonder what the difference is, additives? Didn't buy it but probably should have. BTW- Walmart has the normal kind for $27.97.