All gasoline sold in the United States is required to contain effective detergent additives. Use of additional detergents or other additives is not needed under normal conditions and would result in additional cost. Therefore you should not have to add anything to the fuel.
See also:
External lights
The left-hand stalk controls the external lights and the direction indicators.
The external lights can only be switched on when the ignition key is at MAR. ...
Set-up menu
The number of items in the menu depends on the car settings.
When travelling, only the “Speed limit” indication is enabled.
The “Set-up Menu” enables to perform the following adjustments and/or sett ...
Installation of electric/electronic devices
Electric/electronic devices installed after buying the car or in aftermarket
shall bear the and marking:
Fiat Auto S.p.A. authorizes the installation of transceivers provided that installation
...