Full or Flat ? This issue is

A flat tire (British English: flat tyre) is a deflated pneumatic tire. This may cause the rim of the wheel to ride on the tire tread or the ground, and may result in loss of control of the vehicle or irreparable damage to the tire and wheel.
The most common cause is puncturing of the tire by a sharp object, such as a nail, thereby letting air out. Depending on the size of the hole, the tire may deflate slowly or rapidly

http://en.wikipedia.org/wiki/Flat_tire