Ran Out Of Gas
I've owned my Taurus for 6+ years, and never ran out of gas until today! I had to add 16.9 gallons (including the 2.15 gallons I hiked back with). Based on this I would guess that you wouldn't want to go more than 35 miles unless you are going downhill!
The tank has 18 gal capacity so there was little over a gallon is left in the tank.