Gasoline fuel refers to a type of petroleum-based liquid that is used as a fuel for internal combustion engines in vehicles, such as cars and trucks. It is made up of hydrocarbons, with the majority being octane (C8H18), which allows it to burn slowly and efficiently when mixed with air, producing energy through controlled explosions within an engine's cylinders. Gasoline fuel has a high energy density, meaning that a small amount can produce a large amount of power, making it ideal for use in vehicles.