Well in my first two fill ups after initially having the car I got a little over 15 gallons (with a little topping off - 2 clicks). Now at each fill up, I'm getting any where between lower to mid 16 gallons in the tank, with mild top off (tank clicks off twice). So I don't know if it was a breaking in kind of thing or something else. 16.6 gallons was the most I've put in the Mustang thus far and according to the on board computer I only had 5 miles to E...but 8 days prior to that I only put in 16.1 gallons with only 2 miles E, so I don't know.
I had noticed however, that when I got down to my last 30 miles (or so) before E message, the estimated gas mileage reading started to double up (in some spots) on the number of miles I actually had left before E taking 2 miles for every 1 mile I traveled.
I've never taken my car to the 0 miles to E limit (been close) or beyond, and not sure that I actually would without someone there to give me gas, or without having a gallon of emergency gas in one of those little red tanks inside the car in case the car shut off from the lack of gas in the tank..
For Play: 2011 Ford Mustang v6 Premium Coupe w/Pony Package. Stock...for now.
For Work: 2011 Hyundai Sonata SE. The fun daily driver.