Recently, average automobile weight has shown the tendency of increasing, due, in part, to the the addition of equipment to improve convenience, comfort and safety. At the same time, to help reduce CO2 emissions in the global environment, vast improvment to automobile fuel consumtion is needed. More and more, vehicle weight reduction is being pursued in order to improve fuel economy, but always with a consideration not to sacrifice performance. A design that includes aluminum can be very effective for reducing vehicle weight, however, it is also true that with aluminum there is a concern for increased cost. The use of aluminium alloys in Japan for vehicles started with castings for engines and transmissions. It continues to rival steel for applications in body and chassis components, especially now with the development of higher tensile strength steels. For the expanded use of aluminum, cost effective strategies, such as that of complex part integration, are necessary, to say nothing of the need for a reduction in raw material cost.