Why must the fuel level be checked before a trip?

Checking the fuel level before a trip is essential primarily to ensure that there is sufficient fuel for the journey and to prevent any inconvenience that might arise from running out of fuel. A full fuel tank not only enables the driver to complete their route without unexpected stops but also helps in planning the trip more effectively. If the fuel level is low, the driver can take necessary actions, such as refueling ahead of time or adjusting travel plans to account for refueling stops.

While other factors like checking for fuel leaks, estimating trip costs, and assessing engine performance are important for overall vehicle maintenance and safety, they are not the primary reason for checking the fuel level specifically before a trip. The focus should always be on ensuring that the vehicle has enough fuel to reach the destination smoothly.