The amount of fuel an 18 wheeler carries is important because it determines how far the truck can travel before it needs to refuel. A truck that carries 300 gallons of fuel can travel approximately 1,500 miles before it needs to stop for gas. This means that an 18 wheeler can make a long trip without having to worry about running out of fuel.
However, it is important to note that the amount of fuel an 18 wheeler carries can also affect its fuel efficiency. A truck that carries more fuel will weigh more, which can make it less fuel efficient. Therefore, it is important for truck drivers to find a balance between carrying enough fuel to make their trip and not carrying so much fuel that it affects the truck's fuel efficiency.