PURPOSE: To reduce the fuel cost by attaching tightly from right and left a semicircular iron plate or a semicircular alloy piece to the outside of an electromagnetic pump that is installed in the fuel tank of a gasoline automobile.

CONSTITUTION: Since magnetism of about 80 Gauss is leaking from an electromagnetic pump installed in the fuel tank of a gasoline automobile, to the outside of the pump a semicircular iron plate or a semicircular alloy piece is attached from right and left tightly in order to disperse the magnetism with contact and bring the leaking magnetism lower than 5 Gauss. And, after the travel of a specified distance, the gasoline consumption was measured and it was found that the distance of travel of the gasoline automobile per liter could be made longer a great deal.