http://www.ck12.org Chapter 1. Introduction to Chemistry
FIGURE 1.
U.S. Marine Corps body armor.Transportation
Car bodies were at one time made primarily of sheet metal, which could be pounded out fairly easily in case of
a collision. Today, most bodies are plastic and need to be replaced when damaged. Plastic parts are easier to
manufacture and are lighter in weight than metal ones. Many of the engine components are made of special metals
to increase the lifetime of the engine and to make it more efficient.
FIGURE 1.
A modern car engine.Gasoline and oils are complex chemical mixtures designed to burn in a way that will efficiently produce energy while
emitting a minimal amount of air pollution. The refining of gasoline has improved engine performance but is much
more complicated than simply using the crude products extracted from oil wells, as was common in the late 1800s.
Most gasoline contained lead at one time, because this additive helped the engine run more smoothly. However, this
caused lead contamination in the environment, so new "unleaded" formulations were created that could be burned
smoothly without the addition of poisonous heavy metals. Oils for lubrication have special additives that reduce
engine wear. Some special fuel blends have also been created to generate more power in race car engines.