Reflecting the rising use of aluminum in automobile engines, as many as six new engines planned by the Big Three automakers will use the lightweight metal for introduction between 1991 and 1995, reports a metals industry journal.

Aluminum will be used in the cylinder blocks, heads, covers, water pumps and numerous other components, according to Metalworking News, which notes expanding use of aluminum could push the unit content of the light metal up well past 200 pounds per car by 1995.In 1989 models, the weight is estimated at about 155 pounds. In 1976, the average domestically produced car contained an estimated 85.5 pounds of aluminum.

The publication says an improvement of 60-80 pounds per car over the next six years probably would make aluminum the second fastest-growing material in domestic automobiles, behind galvanized steel.

Currently, all pistons and intake manifolds used in U.S.-built passenger car engines are made of aluminum. The use of lightweight metal is expected to have a beneficial effect on fuel economy in cars produced by General Motors, Ford and Chrysler.