Increasing use of lightweight materials in automobile manufacture will mean lighter cars and resultant fuel economy, reports a metals industry journal.

Expanded use of aluminum will allow that metal to show the biggest gains over the decade of the 1990s in terms of unit content, notes American Metal Market, the daily newspaper that tracks the world metals market.The publication notes that the content of aluminum in U.S.-built cars will exceed 200 pounds by 1995, compared with the current 160-170 pounds per car - a gain of at least 24 percent.

All of the nation's Big Three automakers, it adds, are working on the development of plastic intake manifolds - components that currently are all aluminum. Plastic composite wheels also have been used in production.