Honda CIVIC 2023 Owner's Manual page 35

Models without capless fuel filler
Fuel recommendation: Unleaded premium gasoline, pump octane number 91 or higher
Fuel tank capacity: 12.4 US gal (47.0 L)
a
Unlock the driver's door.
(P188)
b
Press and release the area indicated by the arrow to release
the fuel fill door. You will hear a click and the lid will open
slightly.
c
Remove the fuel fill cap slowly. If you hear a release of air,
wait until this stops, then turn the knob slowly to open the
fuel fill cap.
d
Place the fuel fill cap in the holder.
e
After filling, replace the fuel fill cap, tightening it until you
hear it click at least once.
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