Abstract: An automotive fuel filling system which inhibits automotive fueling from a smaller of two different diameter fuel nozzles. The system includes a funnel assembly having a circular port adapted to receive the fuel nozzle. A nozzle valve assembly includes at least two segments and is disposed in series with the port. Each segment, furthermore, is pivotal between an open and a closed position. When all segments are in the closed position, the nozzle valve assembly serves to prevent dust and debris from reaching the flapper valve. A hook is attached to a radially inner end of each nozzle valve segment and a cam is also attached to each nozzle valve segment configured to provide a clearance between the end of only the larger nozzle and the hooks upon insertion of the larger nozzle, but not upon insertion of the smaller nozzle.