The volume of the tank on your Traveller is 22.4L.
A warning signal rings when the remaining driving distance is 1500 miles. If your tank is empty, you should fill it with the contents of at least 2 x 2L cans in order to switch the warning off.
Even if the tank is empty, you can continue to drive, but as soon as your engine stops, it will not restart. Once you stop the car, it won't restart unless the tank is filled up.
This information can vary on some vehicles of the same model in relation to the options chosen by the manufacturer.