A unique combination of a certain poly(oxyalkylene) amine and a thiadiazole compound when employed as a fuel additive in a hydrocarbon fuel such as gasoline or diesel fuel will preclude fuel gauge sending units from sustaining sulfur-related corrosion damage or restore fuel gauge sending units, particularly silver-based fuel gauge sending units, in vehicle fuel storage tanks to like-new operational condition. Moreover, a method suitable for use in precluding fuel gauge sending units from sustaining sulfur-related corrosion damage or restoring silver-based fuel gauge sending units in gasoline or diesel vehicle fuel storage tanks to like-new operational condition using the combination of a certain poly(oxyalkylene) amine and a thiadiazole compound as a fuel additive is also described.