Auto-Future: Adding Lightness

One of the main improvements in future cars and associated global platforms: weight reduction. Thanks to new, stricter emissions and fuel consumption regulations, this trend is well underway. New cars have already stopped gaining weight. And manufacturers are redoubling their vehicular dieting efforts. Their progress has been predictably rapid. for example, future generations of the European compact class (e.g. Focus III, Golf VII) should shed We more than 100kg, using several strategies…

The increased use of high strength steels allows the use of thinner sheet-metal, although this poses other issues in stiffness, vibration modes and welding processes. The key factor: one can not just replace steel grades. Carmakers must deploy a holistic approach involving changes in manufacturing process. Expect more hydroformed parts and hot stamping of ultra high strength steel grades.

Another, more expensive trend in the body structure: increased use of aluminium and steel in panels and other parts. BMW is committed to this strategy; it already does so in the current 5-series. You can expect an increasingly advanced mix of materials within two car generations. A recent joint-research project of several European manufacturers previews an aggressive mix of different materials (see figure below), although this still poses many challenges in cost and manufacturing robustness.

Of that 100kg expected to fall by the wayside, about a 30kg reduction will come from the body structure. The rest wil be shed from, well, everything else. Car manufacturers are telling their suppliers that new parts must be both cheaper and lighter than the old ones. Careful design and the cost-leverage of global platforms should help git ‘er done, as witnessed by the new Ford Fiesta.

Weight reduction can create a virtuous cycle of further weight reduction. For example, if the overall structure and components are lighter, reduced stress enables a lighter suspension. Light weight opens the possibility of engine downsizing while maintaining performance, or better yet, increasing engine performance with turbocharging…

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