I managed 509 miles on one tank. Actually, the odo indicated 502 miles but was under reporting mileage by 1.4% so the actual mileage was 509 miles.
My lifetime average after over 14,500 miles is 37.4mpg and the last tank, driving from Bryce Canyon to Salt Lake City with some additional mountain driving I got 44.1mpg on a tank that was 416 miles -- needed 9.53 gallons for fillup.
So, maybe I need to start a 500 mile club...
2012 FF Ti HB Sonic Blue, Built 5/7/12, 401A + Parking Technology Package and MFT w/NAV 3.0.2 -> 3.2.2 -> 3.5.1 -> 3.6.2