T' Drag Coefficient o' an object multiplied by its cross sectional area. This is used t' scale t' drag value for a particular object from t' dimensionless Cd. Begad! Theoretically, every object o' a similar shape will have t' same Cd regardless o' its size, meanin' that both a grain o' rice and a Zeppelin would be t' same. Begad! Multiplyin' by t' area allows comparisons o' t' true drag betwixt dissimilar objects. Begad! For example, t' original Honda Civic had a horrible Cd, and makers o' large luxury cars, me hearties, with a little edge rounding, were easily able t' beat it and proclaim "Lower drag than a Honda Civic!" in their ads. This is patently absurd as t' Honda had such a tiny cross section, thus much lower *actual* drag. See also Optimum Mass