There is no doubt in my mind that if they can make a good oil out of the sludge they pump out of the ground, they can make a good oil out of used oil. I base this on the material in your reference and many other things I have read, plus my experience as a chemist. If I thought I found a consistent supply of rerefined oil from somebody with a reputation to protect and at a discount to virgin, likely I would use it. The few times I have seen rerefined oil on a shelf, it has been from some no name. I do have to admit that usually, when I am looking at oil, I tend to ignore anything that isn't in a yellow bottle. The government has strict regulations on labeling rerefined oil. It is funny, nobody needs to have a label on a car saying the transmission housing was once beer cans, or that your kitchen faucet contains old marine fittings, scrap wire, etc. Perhaps BP needs to show us how green they are, or somebody else to show their colors.