Aluminum space frame chassis offer advantages due to the space frame concept and use of aluminum. A comparison is made to a steel space frame and the results reported. Torsional stiffness, bending stiffness and weight are compared. A model was developed using finite element analysis which predicted with accuracy the stiffness and weight of the frames. Using the model, an effective aluminum space frame was developed which was superior in stiffness to steel by 7½% and weighed over 20% less than the steel frame. Stresses were kept below the welded fatigue limit for aluminum allowing welding to be used.