Abstract
In this report the influence exerted by a large vehicle on a smalles one is investigated in a series of static wind tunnel tests. The effects of position on the drag and side forces and on the yawing moment are studied along with the effect of basic changes in vehicle geometry. The forces and moments exerted on a typical car by a large commercial type vehicle are found to be considerable depending upon the relative positions of the two vehicles. These results have been extrapolated to show to a first approximation the effect an overtaking manoeuvre by the car would have on the measured forces which only represent the condition where the two vehicles are relatively stationary.