In recent years, auto makers have been taking advantage of the opportunities for lightweighting and noise reduction made possible by new, advanced adhesives. Now, automakers are getting creative with materials, and BMW is leading the way in combining metals and composites in mass production.
Its newest advance is the use of carbon fiber reinforced plastic, either to provide extra structural rigidity, or for entire components. To keep the driver’s handling experience at a maximum, most of BMW’s lightweighting initiatives are applied above the car’s center of gravity. Thus the ‘carbon core’ (BMW’s term for the use of carbon fiber composites ) has been used for the B and C pillars of the new BMW 7-series, and allows for a lightweight, longitudinal roll bar from the base of the A pillar and along the roof. It’s also used in the roof bows and along the center tunnel as well as the package tray.
The net result of BMW’s lightweighting efforts is a 285 pound weight reduction compared to the 7-series currently in showrooms, and 90 pounds of that is a result of lightweighting the body of the car. Sound insulation provided further opportunities for lightweighting – but not at the expense of driver comfort. The 26 pound weight saving was achieved very simply. Instead of insulating the cabin of the car with soundproofing, it insulated the engine directly, damping noise at its source.