Gasoline is a fuel used to power internal combustion engines. Also known as aliphatic carbon, gas is made from petroleum, a distilled crude oil that is pumped from the ground. The liquid contains hydrocarbon molecules. Gasoline or gas is the common term used to refer to this petroleum-based liquid. Commonwealth countries refer to it as petrol.
Different configurations of these molecules result in gas for various uses. Chains of molecules are linked together. The more chains that are linked, the heavier the gas becomes. Gas is produced from the chains from C7H16 through C11H24, which are blended together.
Although it has had many uses before its discovery as engine fuel, such as a treatment for lice and a cleaning fluid, gas is used primarily to source engines. It was discovered by Nicholas Joseph Cugnot of France in 1769 when he built the first-ever steam-powered engine. Many inventors tried their hand at different versions, but it was Gottlieb Daimler who introduced the modern prototype of the gas engine. His was a vertical cylinder that hosted a carburetor in which gasoline was injected. Invented in 1885 and patented two years later, it became the basis of the first two-wheeled, and then four-wheeled, vehicle.
During the Second World War, a discovery was made that improved the octane rating of gas, simply by adding tetraethyl lead. It was later banned because it caused clogging in the catalytic converter, resulting in a malfunction, and also because it proved to be toxic to the environment. Since it has been banned, gas has become increasingly expensive. To date, only airplanes are permitted to use the lead-based petroleum. A grade 87 octane is the lowest vehicles are permitted to use.
Gasoline has many additives, one of which is methyl tertiary butyl ether (MTBE). MTBE was added to gasoline in 1990 after the approval of the Clean Air Act, although it is claimed that MTBE can contaminate groundwater. If this is found to be true, it is likely that MTBE will be replaced with an alcohol-based liquid called ethanol.
The downsides to the use of gasoline include its hazardous emission of carbon dioxide, which is a poisonous gas, nitrogen oxides, which result in the smog that plagues larger cities, and unburned hydrocarbons, which adversely affects the ozone layer.