Why does my Audi A5 have a lower fuel economy than advertised?

I recently purchased an Audi A5 and noticed that the fuel economy is not living up to the advertised numbers. What could be the possible reasons for this discrepancy?

It is likely that the advertised fuel economy is based on ideal driving conditions, which may not be representative of real-world driving. In particular, factors such as city driving, frequent stops, and aggressive acceleration can significantly impact fuel efficiency.

Another potential reason for lower fuel economy could be due to the use of premium fuel. While recommended for optimal performance, premium fuel can be more expensive and may not be necessary for everyday driving.