See also:

Changing wheels
Your BMW is equipped with run-flat tires as standard. This eliminates the need to change a wheel immediately in the event of a puncture. For information on continuing to drive with a damaged tire, ...

The concept
The tire inflation pressure is measured in the four mounted tires. The system notifies you if there is a significant loss of pressure in one or more tires. ...

Aerodynamic optimisation of underside panelling
As the excellent drag coefficient (cd = 0.26) would suggest, the aerodynamics of the new BMW 3-Series have been intensively honed in a state-of-the-art wind tunnel. The optimised aerodynamics also ...