Steel is still the main component in modern cars. Sixty percent of a car's weight by volume is made of steel.
The steel used in car construction has changed quite drastically over the past century. The steel used in car construction during the 20th century was made by melting iron ore and coal together and then mixing it with other ingredients like limestone. Modern steel is a micro-alloy that incorporates elements like niobium or vanadium, which makes steel stronger and lighter. Improved thermal processing techniques allow metallurgists to cool and reheat steel during different stages of production. This process allows them to create steel that is not only hard, but flexible as well. Modern steel is stronger and 39 percent lighter than older steel, allowing car manufacturers to find new applications for steel components.