Several different cross sections of beam having more than four sides are disclosed that may form a central portion of a beam having end portions that have four sides. The end portions of the beams may be received by frame rails. The central portion of the beam between the frame rails may be formed with more than four sides. The additional sides may be recessed beads or protruding ribs. Beams having arcuate recesses or arcuate ribs may be provided on the central portion of the beam. The end portions of the beams may extend outboard of the frame rails. The ribs or beads on the central portion of the beam may provide equivalent performance to four-sided beams having considerably thicker walls. Weight reduction is achieved because the central portion is made of a thinner material while retaining strength by forming beads or ribs in the central portion.