We need separate gas and liquid content node for fuel tanks. How the heck we supouse to use scripts and logic blocks with this lack of its conents data. If you separate gas tanks and fuel tanks by it's purpouse already ()not allowing us to fill gas tank with fluid), why not make things bit clearer. There is no way to drain NOT custom fluid tanks from fluid fast because pump won't work with low pressure. And there is no way to use logic block to find out if tank is out of fluid when it filled with gas. The way you did it, it requires constant pressure in tank to speed up pumping of fluid. So i can only suggest that you could add additional logic node to separate gas and liquid content.