Shedding pounds on a magnesium diet

Tough CAFE standards are pushing automakers to consider using more lightweight magnesium rather than aluminum, steel, or plastics.

For lightweight car structures, magnesium has always been “the other white metal.” Magnesium is often an afterthought for many North American platform engineers, traditionally an alternative that is perhaps considered late in the game to solve problems with ferrous structures that aluminum might not cure. And even aluminum has become a tougher sell with the arrival of modern high-strength boron and dual-phase steels.

But mounting pressure to cut vehicle weight to meet stringent federal CAFE (Corporate Average Fuel Economy) standards for 2016 has magnesium firmly back on the engineers' table. With the tough federal mandates looming, even the conservative tastes of platform engineers can now be tempted by the potential 40% weight savings that magnesium can offer over steel (20 to 25% over aluminum, which is one-third heavier than magnesium).