Cars don't use jet fuel because it's designed for jet engines, which are significantly different from car engines. Jet fuel is a kerosene-based fuel that burns at a much higher temperature than gasoline, which is used in most cars. The combustion process in a car engine is specifically designed for gasoline, and using jet fuel would lead to damage and potentially cause a fire.
Furthermore, jet fuel is not as efficient as gasoline in car engines. Jet engines are designed to operate at high speeds and altitudes, while car engines operate at lower speeds and are more focused on fuel efficiency.
In short, jet fuel and car engines are incompatible due to the different combustion processes and fuel properties.
