On January 7, 1913, William Meriam Burton received a patent for his cracking process to convert oil to gasoline. On January 1, 1918, the first U.S. gasoline pipeline began transporting gasoline through a three-inch pipe over 40 miles from Salt Creek to Casper, Wyoming.

The terms gasoline and petrol identify and describe the petrochemical product characterized as a transparent, yellowish, and flammable liquid, which is used as a fuel for spark-ignited, internal combustion engines. As the fuel for gasoline engines, gasoline is chemically composed of organic compounds derived from the fractional distillation of petroleum, and later is chemically enhanced with gasoline additives. The fuel-characteristics of a particular gasoline-blend, which will resist igniting too early and cause engine knocking and reduce efficiency in reciprocating engines are measured as the octane rating of the fuel blend; the gasoline blend with the most stable octane rating then is produced in several fuel-grades for different types of motor. Tetraethyl lead and other lead compounds are not used in modern automotive gasoline, except in aviation, off-road motor vehicles, and racing car motors.

Gasoline enters the human environment as an uncombusted fuel as a flammable liquid and as a vapor by way of leakages occurred in the production and handling, transport and delivery. Gasoline contains known carcinogens. When burned, one liter (0.26 U.S. gal) of gasoline emits about 2.3 kilograms (5.1 lb) of CO2, a greenhouse gas, contributing to human-caused climate change. Oil products, including gasoline, were responsible for about 32% of CO2 emissions worldwide in 2021. On average, in the U.S. petroleum refineries produce, from a barrel of crude oil (42 U.S. gallons or about 159 liters), about 19 to 20 gallons of gasoline; 11 to 13 gallons of distillate fuel (diesel fuel); and 3 to 4 gallons of jet fuel. The product ratio depends upon the processing in an oil refinery and the crude oil assay.

Gasoline, also known as gas (in the United States), petrol (in the Commonwealth countries), and benzin (in Germany), is primarily used as motor fuel in combustion engines.

The American English word gasoline denotes fuel for automobiles, which common usage shortened to the terms gas, motor gas, and mogas, and thus differentiated that fuel from avgas (aviation gasoline), which is fuel for airplanes.

Gasoline contains chemical potential energy. The energy stored in the bonds of the hydrocarbons is released when it is ignited. The resulting explosion changes the chemical potential energy into thermal energy, kinetic energy, light energy and sound energy.

Retail gasoline stations in the United States sell three main grades of gasoline based on the octane level: Regular (the lowest octane fuel generally 87) Midgrade (the middle range octane fuel–generally 89–90) Premium (the highest octane fuel–generally 91–95).