@Rich and
@1FastHemi and everyone else with a 50 gallon tank.
I was wondering when the fuel low level tank illuminated. I hit 50 miles of range on the way home and it came on. Fuel level gauge looked REAL LOW, like one needle width off 'E'. Made it home with 47 miles left and parked it on my 4 degree driveway.
After dinner I hit the remote start to go out and filler up. I hooped in and the truck shut off, thought that was strange but fired it back up and that's when I noticed the check engine light. I filled it up with 47 gallons, I can't believe the light comes on with only 3 gallons left in the tank (Owners manual does state light comes on with 3.2 gallons remaining)!!!! When i returned home, the light was still on so i pulled the code with my trusty harbor freight scanner, P0461. Couple screenshots, cleared the code and it didn't come back after a 30 mile loop.
Let me know if your truck throws a P0461/Fuel level Sensor A Circuit Range/Performance when your tank gets low. I don't think I'll be letting it get down below 100 miles till empty anymore.
-cb