What fuel is used in a car?

Gasoline (or petrol) and diesel are the most common fuels used in cars. Gasoline is a refined petroleum product made from crude oil and is typically used in spark-ignition engines. Diesel is also a refined petroleum product, but it's heavier and denser than gasoline and is typically used in compression-ignition engines. These engines compress the air-fuel mixture rather than relying on a spark plug, making them generally more efficient but not as smooth. In some countries or regions, cars may also run on alternative fuels such as ethanol, natural gas, biodiesel, or electricity. The availability and usage of such alternatives vary depending on infrastructure, government policies, and environmental considerations.