full charge

I have a 3D with around 1K miles now that usually charges fully to 300-306 miles of range. Should it at least get to the 310 miles advertised when fully charged? Is there a way to achieve the advertised range or something I just don't understand? Thanks in advance for the education.

If you look at the dashboard picture on the Model S main page, it shows a battery indicator on the bottom left of the screen indicating 242 miles remaining on charge. This indicator is not more than 60% full which would equate to a total range of over 400 miles when charged to 100%. Link for...