I have consistently let it lite up the low fuel warning and exhaust the remaining "range". It has taken no more then 14.2-4 galleons (tank holds 16.6) if I fill up right after the light goes on, so you have quite a cushion.
I take if for granted in the local area, but am more careful on a trip - although I did get 489 miles and filled-up with 15.6 galleons on one leg my trip up north in June. Was getting a bit nervous at that point (although my TT GPS had indicated a number of gas stations and mileage to them in the area that I was going to get off I 81 for a fill-up).
