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:
Additional checks
Every 1,000 km or before long journeys, check and top up if required:
❒ engine coolant fluid level;
❒ brake fluid level;
❒ windscreen washer fluid level;
❒ tyre pressur ...
Central vents
(A) - Air flow opening/closing control. ...
For checking and restoring pressure only
The compressor can be also used just for restoring pressure. Disconnect the quick
connection and connect it directly to the tyre valve; in this way the cylinder is
not connected to compressor and ...