FFH has an actual 14.1gal fuel tank (Topped Off), not 13.5gal. like the OM states. I would think 13.5gal. would be a minimum value. This turned out to take more time than I thought, because there is about 1.7gal. left in the tank when I got to 0miles to Empty. So after putting 28mi. on the FWY, I had to put another 54mi. (82mi Total) on the car trying to run out gas which took another hour and half thinking I would run out at anytime. At 80mi. I was thinking how many gallons does this car hold, it was never going to run out!
When it finally did, it was a non event, it switched over to EV. It gives you a red triangle message to find safe place to stop, I hit OK button to remove the message and EVed it 2miles to a gas station. No big deal. I did have 2gal gas can in the car just in case. Curiously when I restarted the car with gas in it, it started in EV mode and didn't go to ICE mode till after I got going.