The Cd value is the drag coefficient and is the figure generally quoted in publications in relation to a vehicle's aerodynamic qualities. It is used as a comparative value to assess the aerodynamic efficiency of the shape of a body, regardless of the body's size. A number of variables influence the Cd value, including the vehicle shape (s [..]

The Cd value is the drag coefficient. It is measured in the wind tunnel and sums up the vehicle’s aerodynamic qualities. This comparative quantity describes the "formal quality" of bodies, irrespective of their size. A number of factors influence the Cd value, including the vehicle shape (saloon, estate or hatchback). Narrow gaps and join [..]