The drag coefficient is a dimensionless quantity that represents the resistance of a vehicle to the air. It is measured by dividing the drag force by the product of the air density, the frontal area of the vehicle, and the square of the velocity of the vehicle.
A higher drag coefficient means that the vehicle will experience more resistance from the air, which will result in reduced fuel efficiency and performance. A lower drag coefficient means that the vehicle will experience less resistance from the air, which will result in improved fuel efficiency and performance.
The 2009 Audi A3 has a drag coefficient of 0.32, which is a relatively good value. This means that the A3 is relatively aerodynamic and will experience less resistance from the air than some other vehicles.
