Unleaded gasoline is a type of fuel used in most modern vehicles. It is designed to power internal combustion engines while minimizing harmful emissions. The absence of lead, a toxic additive used in older gasoline, makes unleaded gasoline safer for both the environment and human health. This fuel typically comes in different octane ratings, such as 87, 89, and 93, which indicate its ability to resist knocking during combustion. Unleaded gasoline is widely available at gas stations and is the standard choice for cars, trucks, and other vehicles manufactured since the 1970s.