Body Shell

Body Shell







The structural rigidity of the E46 body shell was increased using computer aided design (CAD) techniques. Every component of the new body structure was designed using this method. CAD allows the design to be translated into computer aided manufacturing (CAM) more efficiently. To reduce the weight of the vehicle, while retaining strength, high strength steels are used and now amount to 50% of the body shell weight.

The second area of focus of the body shell is "structural dynamics". This deals with vibration frequencies that effect the ride quality and rigid feel. The E46 body shell was designed so that the frequencies for torsional twisting and bending are separated and are in an inaudible range. The ranges match the E39 for twisting at 29 hertz and bending at 26 hertz.

The E46 continues with BMW's safety cage concept for passenger protection. The tubular impact structures continue to provide protection against body damage during front or rear impacts.