Lightweighting is the No. 1 challenge facing automotive engineers today. Manufacturers are scrambling to build vehicles that contain a variety of weight-saving materials, such as aluminum, carbon-fiber composites, high-strength steel, magnesium and plastic.

The need to reduce vehicle weight has spawned myriad new technologies for assembling aluminum, high-strength steel and other materials. These new technologies include self-piercing rivets, flow-drilling screws and friction-stir spot welding.

DEARBORN, MI—Ford Motor Co. has developed new carbon-fiber wheels for its carbon-fiber-bodied Ford GT supercar.

Efforts to reduce vehicle weight have mostly focused on aluminum, plastics and composites, but another lightweight material is also getting attention: magnesium. The ninth most abundant element in the universe, magnesium is as strong as steel, but 33 percent lighter than aluminum, 60 percent lighter than titanium, and 75 percent lighter than steel.

ARaymond Automotive has provided custom fasteners, clips, connectors, adhesives and other materials to OEMs and Tier 1 suppliers around the world for nearly 20 years. Its engineers specialize in three processes (fastening, fluid connections and bonding) that are used in all areas of a vehicle.

WARREN, MI—General Motors engineers have developed a technique to join steel to aluminum with resistance spot welding.

Back in the day, engines were the exclusive domain of cast iron and steel. But, during the past decade, more lightweight materials, such as aluminum and hard thermoplastics, have been slowly creeping under the hood. The Holy Grail, an engine made almost entirely out of plastic, is finally close to reality.

Friction stir spot welding has many advantages compared with riveting or resistance spot welding.