ABSTRACT
This chapter provides the introduction of lightweight structural materials. Material choices for products are balances between energy, waste and safety that depend on their historical context. The chapter moves on to discuss three alternatives: steel-based multi-material; all-aluminium; and all-composite. The concept 'all-aluminium' would save 4.6–5.1% energy, but would increase waste by 52 kg. The concept 'all-composite' would save the most, 11.2–11.3%, but would also increase waste by 166 kg. The chapter presents various alternative concepts for the structures of mid-class passenger cars, each based on proven technology. It discusses how lightweight materials can reduce the energy use of motorised road transport, with composites offering the largest reductions. The public image of lightweight cars as unsafe does not help either—safety is still a major reason for people to buy larger cars. All major car companies have sizeable interests in the materials production sector and strategic partnerships are the norm rather than the exception.
