I had often wondered the same thing about my Yukon. How far can i go? The electronic display tells you how far you should be able to go, and at about 33 miles it changes to Low Fuel Level. This is right about the same time the light comes on. I rember once i was using the trip guage and was just past 33 miles when i felt the truck start to sputter. Fortunately i only had about 200 yards to go before i pulled into the gas station.
Long Story Short: 33 miles