Abstract: A fuel-saving device is disclosed. The device comprises a radiating members unit having a plurality of radiating members arranged in spaced-apart and arranged in an alignment; net body for mounting to each of the spaced-apart radiating members, wherein the fuel-saving device is disposed onto the front end of a catalyst sensor of the exhaust pipe of a vehicle, energy elements of the radiating members convert the oxygen ions to ultra micro particles and the collision of the oxygen particles causes the gas stream molecules to generate naturally turbo which produce propel action and a micro explosion of oxygen particles, the oxygen particles enter the cylinder of the vehicle enhance complete combustion of gasoline.