Most rentals come with a full tank of fuel but that’s not always the case . There are several policies you should understand before you Book Budget car rentals at Dallas/Fort Worth airport. If you refuse the fuel service option and rent a car with fuel, you will be requested to return the car with the same amount of fuel, and if you fail to return it with the fuel, the company counts the fuel service charge in rate per mile and they will deduct from your deposit. If you accept the fuel service, you will pay according to the terms of the contract and you can avoid the fuel service charge by returning the car with the fuel approximately to the one that was in it before hiring. Also, ensure you refill the tanks with the correct type of oil and avoid using ethanol fuel even if the vehicle states that it’s a fuel flex vehicle.