It's the human driver that costs money. Fuel is a very tiny part of that, especially in the US (compared to the EU) where fuel is practically free.
7 USD is 5.99 EUR. That would be 1.58 EUR/liter. They aren't just approaching that, that is pretty much exactly the current price for gasoline with 10% Ethanol added in several German cities that I checked, with some fuel stations cheaper and some more expensive.
If you need E5 (older cars can't handle E10), you'll pay more than that.
Bloomberg have a nice visualisation tool : https://www.bloomberg.com/graphics/gas-prices/#20202:United-...