It’s always tricky sorting out how to operate a new vehicle! To open the gas tank on a Mazda 6 from 2017, push the gas cap release button to the left below your steering wheel.
To locate the button, start by sitting in the driver’s seat. Looking at the steering wheel, you’ll see a stability control toggle directly to the left. About six inches below that, you’ll find your hood latch release button. Directly beneath that are two buttons: the rear hatch release button on the right-hand side and the gas cap release button on the left-hand side.
Push the gas cap release button until you hear the gas cap pop open. From there, you can unscrew the cap and access your gas tank.