Automobile door “skins” are the outermost surfaces of the doors (such as seen in Figure XXXXXXXXXXThey are usually made from sheet steel, but the pressure to reduce weight leads car makers to consider...

Automobile door “skins” are the outermost surfaces of the doors (such as seen in Figure 8.25). They are usually made from sheet steel, but the pressure to reduce weight leads car makers to consider aluminum or sheet molding compound (SMC) as alternatives. A set of four steel door skins for a GM Holden mid-sized sedan weighs 17.0 kg. It is estimated that a replacement set made from aluminum would weigh 10.5 kg, and one made from GFRP would weigh 11.7 kg. If both the steel and the aluminum contain 50% recycle content, and the vehicle (with steel doors) weighs 1,400 kg and will be driven 150,000 km over its life, will the substitution of aluminum or SMC for steel save energy? Use the CES Eco-audit tool to find out.