In-vehicle fuel tank device and utility vehicle

An in-vehicle fuel tank device, comprising:

• a tank body, integral with and forming a main tank and a sub tank, the tank body comprising a top portion, a side portion, and a bottom portion;
• and
• a fuel pump configured to supply fuel to an engine, and
• wherein:
• the bottom portion comprises a first area constituting the main tank and a second area constituting the sub tank,
• at least a portion of the first area has an inclined surface that becomes lower toward the second area,
• at least a portion of the second area is depressed to serve as the sub tank configured to receive and store fuel having flown along the inclined surface, and
• the fuel pump comprises a suction filter inside the sub tank
• the first area and the second area border on each other in a boundary area in at least a portion of which a barrier protrudes upward from the boundary area and into the tank body such that the barrier inhibits fuel from flowing from the second area to the first area,
• the boundary area comprises coplanar flat portions disposed between opposite ends of the barrier and the side portion in the boundary area, and
• the flat portions extend from the first area to the second area and allow fuel to flow from the first area to the second area.