Which refueling method allows more fuel to be pumped into the wing tanks?

The method that allows more fuel to be pumped into the wing tanks is over the wing gravity refueling. This system relies on gravity to move the fuel into the tanks, which can facilitate a smoother flow and reduce the risk of back pressure that can occur with pressurized systems. Since the fuel flows freely under the influence of gravity, there are fewer restrictions, allowing for a potentially greater volume of fuel to be added simultaneously, especially if the fueling apparatus is positioned high enough to maximize gravitational flow.

In contrast, while a pressurized fuel system can deliver fuel quickly, it may be limited by the pressure capability of the system and the design of the fuel tanks. Single-point refueling systems provide a convenient way to refuel but usually do not surpass the capacity that can be achieved through gravity feed from an elevated position. Manual refueling systems might not be as efficient or effective in delivering large quantities of fuel compared to gravity refueling, as they often rely on human operation which can introduce delays and limitations in flow rates.