The origins of drag and lift reductions on automobiles with front and rear spoilers.

Front underbody dams and rear deck lips ("spoilers")have been in use for some time as aerodynamics aids for automobile drag and lift reduction. However, the flow field effects and associated surface pressure changes witch produce these improvements have not been well understood. Aerodynamic lift and drag contribution of various model components, ass well as the changes produced on these components by the addition of "spoilers", have been determined. Flow field mechanics witch will produce the observed pressure and force changes have been proposed.