Most of the metal used to make cars is steel, which is an alloy of iron and carbon, explains HowStuffWorks. Aluminum is the second-most used metal in the automobile industry. Although there are other metals used, such as copper, platinum, palladium, rhodium, tin, lead and a few others, steel accounts for more than half of a car's weight, according to The World Steel Association.
The wealth of manufacturing methods available allows many different kinds of steel to be made for cars. Stainless steel, for example, plays a prominent role in the makeup of the exhaust. More exotic metals, such as palladium and rhodium, are used in the catalytic converter, which reduces or eliminates the harmful emissions of the exhaust pipe.
In 2007, the average car used 2,400 pounds of steel, 327 pounds of aluminum, a percentage of copper, just over a gram of platinum and widely varying amounts of the other metals mentioned above, according to Hard Assets Investor. The lead is used mostly in the batteries, which also contain the protective metal zinc - which serves a coating function against oxidation. Basically, zinc protects other metals from the elements. Tin is employed in the soldering elements of a car.