Fuel tank for a vehicle comprising a filler neck for receiving a diesel fuel filler nozzle

The vehicle fuel tank has a filler pipe (2) whose inlet is restricted by swiveling plates (3a, 3b). These are mounted on arms (4) with an upper section (4b) which tapers towards the inlet. A spiral spring (5) is fitted around these sections, so that the plates can be pushed apart when a large diameter diesel pump nozzle is inserted, but not by a petrol nozzle of smaller diameter.