Abstract
This paper presents a method of estimating the drag coefficient of a motor vehicle to an accuracy of about ± 7%. In this method, the vehicle is divided into nine feature categories, and rating numbers are assigned to each category depending on the merits or demerits of the particular design. The method is not intended to be a substitute for wind tunnel testing, but to provide guide lines for stylists so that they can avoid undesirable body features in the early stages of design.