[Quadraria10]

Better yet go to Fuelly.com and look at real world gas mileage reports for different models. You will notice that almost none of them match the official fuel consumption stats.
If you want better gas mileage you need to drive a smaller 2 wheel drive car, if you want worse fuel economy buy a truck or a full size SUV. If you practice hypermiling techniques you could probably improve your fuel economy by 10 to 20%.

 

[Quadraria10]

Hate to break it to you, but shy of changing the way you drive, and where-- increasing your tire pressure, and adopting hyper mileage driving techniques are about the only way you will get better mileage.