05 Screw, 5.4, 6K Miles.
Sticker says I have the 30 gallon tank.

I never really ran it down too far, but when I get close I still only get 20-25 gallons in it.

How far can you go on empty?
Is there an idiot light that comes on when its low?
How many gallons are left if/when a light comes on?

I had a wierd occurance this morning, I was driving to work, 20 miles, basically flat, I was just above the redline on E, then by the time I got to work the gauge was way off the E and almost had a quarter of a tank! Anyone else notice this at all?

I know my fathers old 90's F150 had dual tanks with a switch, I'm wondering if Ford had some sort of automatic reserve tank now that kicked in? Who knows, I'm probably just daydreaming.

TIA
Paul

 

ON AVERAGE YOU SHOULD GET AND ADDITONAL 20 TO 25 MORE MILES BEFORE YOU SHOULD HAVE TO FILL UP. I'VE DONE THE TESTING ON MY 2004.
THE GAUGE WARNS YOU AT 50 MILES TILL EMPTY, BUT UNTIL YOU HIT THE O MILES TO EMPTY MARK YOU WILL HAVE THE ADDITIONAL 25 TO 30 BUT I WARN YOU THIS IS ONLY AN ESTIMATE. YOUR MILES MAY VARY DEPENDING ON YOUR DRIVING HABITS.

 

I'm not sure about the "new" models, but in my '02 S'crew I have aprox. 3 gals. left when the "low fuel" light comes on. About the "quick change" on the gauges, mine will run about 200 miles to the "half" mark, then only another 100 miles to the "E". I've learned to live with it, as I'm sure it is due to "topping off' the tank. Good Luck

 

On the fuel gauge indication display, the tank sender is a floating arm such that the arm location is not a linear travel vs fuel level relationship.
If you look at the dash gauge, it is layed out in a linear scale fashion.
The two don't match in a technical sense. So the indication can never be all that accurate.
On another note the dash gauge is not a continious (instant) readout but is updated by the dash micro-processor.
So you have several different actions that have not been very well coordinated by engineereing. This has been the case for a long long time (many years) so it seems not to be of hi importance.
On an 02, I have run it down to the red indicator several times and concurr there is about 20 mile to spare on the average. The owners manuel addresses this point.

 

Just don't let it get that low.

I ran my '03 down way past E one day and when I filled it up I put in 24.487 gallons. Not bad for a 24.5 gallon tank huh? Honestly tho, I was an idiot that day. I normally never run my tank that low. I fill up when it's less than 1/4 tank. If I recall tho, my low fuel light came on in Shaumburg on I-90. I pulled in the station in Rockford to fill up. So that would have been about 60 miles give or take. I was getting a little squirmish before I finally pulled off the interstate.

 

All gasoline contains "stuff" that settles at the bottom of your tank over time. When you put too many miles after the tank reads E you run the chance of fouling up your fuel delivery system and sucking up some of this "stuff" into your fuel filter and maybe past it.

As others have said, try to fill up when you reach 1/4 of a tank. And never fill your tank when the delivery truck at the station is in operation; it stirs up the "stuff" and it does get pumped into your tank.

 

Call me crazy but I like to live on the edge. I guess you can call driving my truck until the fuel light comes on the "edge". The owners manual says that I have a 30 gallon fuel tank, so I had to see how many gallons that it would actually hold.

I drove until the light came on and drove approximately 30-40 miles after that until I decided that I had gone far enough. So, I go to the gas station and go to the pump that is parked on the hill leaning to the right so that my fuel tank will hold as much as I can put in there. Now I am the person that doesnt stop filling the tank when the first "click" turns the nozzle off. No sir. I pump until that b_tch is absofreakinglutely full. It took me about 10 minutes after the first click to fill it all the way up. I normally put at least 4-5 more gallons in my truck after the first click.

By the way the pumps that arent primed really well work the best because they dont pump really fast and you can let the fuel leak into the tank when you get close to the top. My conclusion:

My 30 gallon tank will hold 33-34 gallons filled to the top of the tank. At about 15 miles per gallon I can get at least 450 miles until the fuel light comes on and then I fill up at about 30 miles after the light comes on.

By the way I have the '05 Screw 5.4. Hope this helps.

 

tbizzle,

Years ago it was rumored that this practice of continually overfilling the tank was hard on the tank sending unit...bent the float arm or something like that, eventually making the gauge inaccurate or even inoperative. I used to do that on my previous vehicles, and sure enough I had a couple of gas gauges go south on me.

Now my cases might be just coincidence, and those old rumors could well be old wives tales, but I for one no longer do that. One click after the first and that's it for me.

Paul2, back to your questions, my current experience with my 01 probably does not relate much to your 05, but for what ever its worth...my low-fuel light seems to come on fairly consistantly when I have used up 21 to 21.5 gallons of my 25 gallon capacity.

 

There is one other issue with filling your tank that full. If you fill it up and then say go home and park in the driveway and the ambient temp goes up, the fuel will expand and leak out of the cap or put added pressure on all of the other seals. I never stop after the first click either but I usually only put about another gallon in after the first auto shut off.

 

to test my theory i was towing one week and put it to the test by seeing how far i could get towing. results it did not work and ran out of gas on intrastate. lukily a trooper came by and rescued me. so i don't even try it when towing. first beep and i'm looking for petro. overall though i'm like the other dude, i like living on the edge. sounds crazy but its me not you. later. out. b.d.

 

I guess it is a good thing I have the 100,000 mile warranty.

 

I'm not sure where the fuel pump is on the ford, but on my last vehicle - a crappy dodge - the fuel pump was located inside the gas tank. I was told never to let it get too low. The pump is cooled by the gas in the tank, and when the fuel was low, the pump could heat up and malfunction. I don't usually let it go too far below 1/4.

 

I think nearly every vehicle made today has an electric fuel pump in the tank. I also think that as long as there is enough fuel in the tank for the vehicle to run, the pump is in no danger of overheating.

But...if you ever do run out of gas, remember to go ahead and turn the ignition off as soon as possible, because in that case the pump will be running dry and soon overheat.

 

I have run as much as 50 - 60 miles after the low fuel light came on. (03 4.6 screw)
Another reason to not wait until you are bone dry is b.c its a b!tch to shell out 65- 75 bucks to fill er up
-Patrick