This report details the design and implementation of wind tunnel tests to evaluate the aerodynamic performance of individual members of 2,3, and 4- vehicle platoons. The purpose of the tests described here is to quantify the behavior of vehicle drag, or--or more properly--drag coefficient, as a function of vehicle spacing. One-eight scale models of the 1991 GM Lumina van are used as the prototype vehicle. The design and fabrication of force balances capable of measuring drag, side force and yawing moment is described. Models are mounted above a porous ground plane surface designed to control the surface boundary layer thickness.