As fuel efficiency climbs the list of automotive features that interest consumers most, hybrid and electric vehicles are moving from niche technology to mass adoption. According to JD Power and Associates, hybrid vehicles accounted for 2.8% of U.S. automobile sales in 2009 and that number is expected to climb to 7% by 2015.

However, the technologies that enable these vehicles' fuel saving capabilities are also deeply reliant on rare earth metals and magnets. 

Lanthanum and cerium are key elements in the nickel metal hydride (NiMH) battery that powers virtually every make and model of hybrid on the road today. The two rare earth elements are part of the negative electrode in what is the most common electrochemical combination for NiMH batteries. 

In electric vehicles (EVs), the electric motors that eliminate the need for gas altogether use neodymium-iron-boron (NdFeB or neo) magnets, blended with dysprosium and praseodymium. The neodymium gives the motors high power with reduced size, and the dysprosium allows the magnets to perform at high temperatures without losing their magnetic performance.  

While rare earths have particular importance in hybrids and EVs, all automobiles use rare earths:

Cerium is used to polish the glass and it helps to absorb UV sunlight rays, and it is also used in the catalytic converters.

Neo magnets are used in the small motors that enable power window, seats, sunroofs and more.

Europium, terbium and yttrium enable the color in LCD screens that are increasingly a part of the modern automobile.