From what I can tell this is a tax if it's charged to the oil companies. Here is the definition of a fee "In general a fee is a voluntarily incurred governmental charge in exchange for a benefit conferred on the payer, which fee should somehow reasonably approximate the payer's fair share of the costs incurred by the government in providing the benefit." I actually don't think it matters what you call it eventually the folks who use oil will pay for it. This includes higher price for shipping, plastics, etc in addition to higher gasoline/diesel prices. I actually think it's worthwhile to tax fossil fuels but the oil companies will not be able to eat it. If you look at the rate of return of oil companies they are much less than many/most industries. It's extremely capital intensive and very risky business compared to Apple, Google Facebook, etc.