The Super Fuel is a game mechanic. Adding Super Fuel to a plane will make the plane's time to return decrease by 10%. This can be used for planes that take a long time to return like the 1930s Racer-GeeBee which takes 12 hours to return, this makes it take 10 hours and 40 minutes instead. Super Fuel can be collected from the Super Refinery or it can be bought from the special section of the store. You can buy 25 Super Fuels for 1 AirCash and 400 Super Fuels for 15 AirCash. You can view how much Super Fuel you have, as it appears as a bar between the XP and the Passengers. Clicking the bar will automatically open up the special section of the store. You can not directly buy Super Fuel with real money but you can buy AirCash which is used for buying Super Fuel.