It’s easy to open the gas tank on an Alfa Romeo Stelvio or Giulia. You simply turn the ignition off, ensure the car is unlocked, and gently tap the gas cap itself, pressing it in a little and then letting go. It should pop open with ease.
Your Stelvio’s gas cap won’t open if the engine is running or the doors are locked. You may have tried opening the gas cap by tapping it, but had your car doors locked or forgot to hit the push button to start to power the engine down. It happens!
Gas caps sometimes get frozen in winter months, too. In this case, gently tap the gas cap repeatedly to break up and loosen the ice, and you should be all set.