Why does my Audi A7 have poor fuel economy?

I have noticed that my Audi A7's fuel economy has been declining lately. What could be the cause of this and how can I improve it?

First, make sure to regularly check your tire pressure, as under-inflated tires can drastically affect fuel efficiency. Also, consider using a fuel additive to clean your engine and improve fuel economy.

Another common reason for poor fuel economy is a clogged air filter. Make sure to replace it every 12,000-15,000 miles or as recommended by your owner's manual.