A motorcycle fuel tank according to a preferred embodiment of the present invention includes an upper shell, and a lower shell including a body and fixing portions. The lower shell body is bonded to the upper shell and arranged to define a fuel storage space with the upper shell. The fixing portions are used to fix the lower shell body onto a motorcycle body. The lower shell is made of an aluminum alloy and the lower shell body and the fixing portions are formed by a casting process such that the fixing portions are integral with the lower shell.