<http://schema.org/about>
"Making vehicles lighter is a great way to reduce energy consumption, but aluminum is a very energy-intensive material to make. Is it worth it to make vehicles out of aluminum?"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/cars/make-sense-make-vehicles-aluminum-how-long-energy-payback.html>