The C-section bumper design has become a de-facto engineering standard for the majority of thermoplastic bumpers on production vehicles. C-section beams can provide satisfactory performance in a wide range of crash scenarios and can be produced using a variety of plastics processing methods. However, owing to changes in bumper design requirements and advances in composites technology, recently many OEMs have begun considering use of I-section geometry, which has the potential to provide significant weight and packaging size savings while providing equivalent performance at a lower cost. This report will compare the performance of C- and I-section designs using a variety of different compression-moldable, glass-mat thermoplastic (GMT) composite materials. A software package will be introduced that makes it possible to evaluate an I-beam design for a given set of packaging requirements in a very short period of time. Processing details and costs for each approach will be considered, and a new method for integrating the mounting stays on the I-type beam will be described.