Using the below url as a guide the fuel consumption per amount of fuel transported is actually very economical.
Deadweight: 442,470dwt, Lightweight: 67,000t = 375,470t of cargo. Fuel usage 141t per day. With a 15 day trip that would mean using 2,115t of fuel to get 375,470t of crude to its destination.
https://www.wartsila.com/encyclopedia/term/ultra-large-crude...