The aim of this part of ISO 15403 is to provide manufacturers, vehicle operators, fuelling station operators and others involved in the compressed-natural-gas vehicle industry with information on the fuel quality for natural gas vehicles (NGVs) required to develop and operate compressed-natural-gas vehicle equipment successfully.Fuel meeting the requirements of this part of ISO 15403 shoulda) provide for the safe operation of the vehicle and associated equipment needed for its fuelling andmaintenance;b) protect the fuel system from the detrimental effects of corrosion, poisoning, and liquid or solid deposition;c) provide satisfactory vehicle performance und