Why does my Audi A7 have poor gas mileage?

I've noticed that my Audi A7's gas mileage has been significantly lower than what is advertised. What could be causing this issue?

Make sure to properly maintain your vehicle by regularly changing the oil and air filter. Also, try using a higher grade fuel to see if that improves your gas mileage.

Is your tire pressure at the recommended level? Low tire pressure can greatly affect your gas mileage. Also, try avoiding heavy acceleration and speeding on the highway.