To feed high-density fuel into an engine by cooling fuel in a feed pipe, to improve fuel economy by preventing abnormal fuel, to return low-temperature fuel to a fuel tank by cooling fuel in a return pipe, and to prevent deterioration in the durability of a fuel pipe component or a fuel pump disposed in the fuel tank.

In the fuel cooling device for a diesel engine vehicle, in a vehicle side view, a forward inclined portion forwardly inclined along an engine hood is formed on the front portion of an engine cover and also a backward inclined portion with a clearance with the engine hood increased is formed behind the forward inclined portion. The feed pipe and return pipe are formed with radiation portions composed of metal pipes, and the radiation portions are arranged on a rear side from the backmost end of the backward inclined portion of the engine cover and also arranged to be exposed upward beyond the upper surface of the backward inclined portion.