Re: 0W-40 oil discontinued
if you read the entire article on wiki, you'll see that it begins fossil based in most occasions, I do see the reference to completely man made. But My vendors reps including mobile one and castrol both tell me it starts as crude, then is super refined. Like I said I'm not a chemist, or expert but getting materials from oil sands and hydrocarbons sounds crude based to me, read the whole thing. Maybe in war times it was different?