Info from my session with the Ford tech...(Note: Mine is definitely NOT a gauge issue...and I have MFT.)
Took the car in last week at 3 miles DTE. Went with the tech to fill the car up while he had his computer connected to the car. Said it showed 10% fuel in the tank (so, about 1.5 gallons of a 16.5 gallon tank). I filled it up and it shut off at 12.6 gallons on the first click. He said the computer showed the tank at 90% full and asked me to pull the nozzle out slightly and try again. This took me into uncharted territory at 13.4 gallons. We waited a minute and tried again...this time we got to 13.8. At this point the computer said 98% full. He asked that I keep trying which I did...each time with the nozzle slightly pulled out from the car. (If I pushed it all the way in, it would click off immediately). After about 7 more clicks we ended up getting 15 gallons into the car. The whole process took about 20-30 minutes...much longer than I ever plan to spend filling my car. At the point we stopped, the computer still said 98% full
He then put the car up on the rack and did some more investigating...he will be updating the hotline with the information he gleaned from my car today and said several times that he does think it is an engineering issue. He confirmed that the venting system was working properly in terms of the back-pressure in the system during the fill and before and after which also suggests that the issue is a design issue internal to the tank.
The positive is that I have a full tank of gas for the first time since owning the car. The downside is how long it will take me to get the car full going forward until they can get a response from Ford. He was leaning towards taking the action of replacing the tank, but was concerned that he would get another tank with the same issue since there is no clearly identified way of knowing which thanks have the problem.
Additionally, we were able to confirm that the fuel gauge was reading correctly for the amount of fuel left in the car.
What this all means to you folks is that when you take your cars in, you can tell your technicians that there is an entry in the Hotline system for a problem very much like what you are dealing with. My technician was able to find 3 other Hotline entries that he was using as reference.
(Note: I also posted this on the Blue Oval forums thread on this topic.)
2013 Ford Fusion Titanium - BLK TI "Eleanor"