a fuel tank protective cage and mounting device for a vehicle such as school bus including a shelf section that is welded to front and rear sections and to right and left longitudinally extending members to provide a protective cage that is a totally welded structure . the right and left longitudinally extending members protect the fuel tank from puncture by the edges of the lower flange of the frame rails and also adds considerable strength and rigidity to the protective cage and mounting device . the protective cage is secured to the outer vertical surfaces of the frame rails and the fuel tank is located between the frame rails and secured to the cage .