I'm getting 9 MPG in the city no matter the driving style. I really think there's something that is causing this, maybe you guys can help.
To give you some background about the car, it's a 2007 Crossfire Limited Automatic NA.

New air filters, new sparkplugs, new fuel filter.
The mass airflow sensor got cleaned.
New tires, wheel alignment, etc.

Everything seems fine, the car behaves normal.
From all the research I did, what's left would be the injectors or the oxygen sensor, I didn't change those.

Let me know what you guys think and if you experieced something like this.