Prepaid fuel charges appeal to a customer’s need for simplicity and to concerns about being late, as stopping for fuel can increase the risk of not making a departure deadline. Airport security has lengthened the departure process, and rental companies have formulated new refueling options. Unless a customer knows they will return the car with an empty tank or they have an early flight, they shouldn’t opt for prepaid fuel. In all cases, the cost to have the agency refuel the car is higher than that incurred when the driver fills the tank.