Short answers, pulled from the story.
Gasoline is a transparent, yellowish liquid that powers the modern world and became a fuel only when engineers in Germany developed the Otto engine during the final quarter of the 19th century. Before the late 19th century, the volatile hydrocarbon known as gasoline was often discarded as a dangerous byproduct of coal gas production.
Commercial gasoline is a complex mixture of hydrocarbons containing between four and twelve carbon atoms per molecule that is produced through refining processes like reforming and isomerization. A single barrel of crude oil yields roughly 19 to 20 gallons of gasoline, alongside 11 to 13 gallons of diesel and 3 to 4 gallons of jet fuel.
The global phase-out of tetraethyl lead began in the United States in 1973 and was completed worldwide by August 2021. This additive was widely adopted in the 1920s to prevent engine knocking but introduced severe health hazards that led to its eventual elimination from road vehicles.
Winter blends of gasoline have higher Reid vapor pressure to ensure easy starting in cold weather, while summer blends have lower vapor pressure to reduce ozone emissions and smog. These composition changes are necessary to meet specific operating conditions and environmental standards throughout the year.
The combustion of gasoline produces approximately 8.89 kilograms of carbon dioxide for every gallon burned, contributing significantly to global climate change. Transportation is the largest source of carbon emissions in the United States, accounting for 30 percent of the total carbon footprint.