I didn’t go out to purchase oil and make a small profit. I stocked up for myself, and selling off 60 quarts to cover my own stock netting free oil for over a year on various vehicles of mine.
So you are "selling off 60 quarts to cover your stock." You and your friends are getting free oil, which was your plan from the start. But you "didn't go out to purchase oil and make a small profit" ???
There is no difference. You are trying to profit / benefit / get ahead. There is nothing wrong with that. I applaud your creative, entrepreneurial spirit. Almost everyone wants to save a few bucks. And this site has a "for sale" section, so that's fine too (IMO). But please don't try to play it off like profit was not your plan.
I wonder what Pennzoil would say about your status as a non-authorized reseller... 15 gallons is a quantity worth their consideration.