Hi all.
First time post.
This question may of been posted,
I just got this new F-450 6.4L,.
With an Altec Boom on it.
"A Bucket truck"
On the first week I was asked to help one of our system out in Texas with IKE storm damages.
From SC To TX. When I filled up, my Fuel gage said I had 325 miles remaining.
It was a smooth ride until I got into Louisiana,
Pretty bumpy in constructions area
Since then after each fill up, it said I had 225 miles remaining.
Is this a computer malfunction?
How many miles does your computer sais after fill-up?

 

The estimated miles to empty are based on the average miles per gallon that the truck has been getting. This average is not effected by resetting the average miles per gallon.

 

The above is correct. The default setting is what was there when you bought it. As the PCM has learned your real driving habits/conditions and actual mileage it has adjusted the estimate.

The only real way to tell your mileage is to start full. When you fill up again take your actual miles driven divided by actual fuel put in and then that will give you a better predition.

 

Guys, I disagree with the above posts. I have filled up many times. When you clear, you can clear miles, mpg, time, etc. I clear everthing if I want to measure mileage.
My on board computer and my manual calculation comes out near identical all the time. I DO NOT BELIEVE that it retains info from previous fill up, UNLESS, you do not clear. I have a King Ranch dash, which is somewhat different from other models.

 

I don't know how it does it but it's accurate. Once I needed 6 more miles to get fuel at a station and the read out said I had 2 then 1 then 0. When it hit zero I ran out. I never thought it would stop at 0. I figured I'd have at least 6 miles left. I was sputtering real bad so I pulled over as not to fill the system full of air. Once I had 2 gal.s of fuel from a TowTruck It started right up and off I went.
Today I did the same. But this time I made sure I had at least 5 miles remaining on the message center. No more 0's..

 

I think it depends on the truck and how you drive it. I have had mine to 0 before and still got several miles more out of it to get to the fuel station.

 

I wouldn't be running much below 1/4 tank for regular fill ups if I were you. Not good for the electric pump and not good for injectors to run dry. If you are doing this all the time its going to cause you problems. On the miles to 0, mine is pretty good so long as the driving is consistent, it needs several tanks of the same type, hwy empty or hwy pulling and then it will be closer to accurate. When that low fuel light comes on, you should be filling up. If you are pulling or heavy weight all t he time, an additinal fuel tank is ideal to save on stops for fuel. When I am on long trips I like to carry 10 gallons of diesel in case I get stuck between stops and can't get diesel.

 

Sorry Let me backup here a little bit.
The truck was in Indiana wad driven to KY at the Altec plant, where it was fitted with the Altec boom. And from there it was driven to my office.
When the driver got here the truck had already have 1600 miles.
The first 5 tank the computer would register anywhere around 325 to 350 miles remaining.
It's only when I reached the construction area in Louisiana, "It was so bad it ejected my GPS from the dash unto the floor" And from there on when I fill up it sais I got around 225 sometime a little more, miles to go.
Here are the specs from the specs that came with it.

6.4 V-8 diesel
Torkshift 5-spd auto trans
4.88 ratio regular axle
16000 GVWR package
40 Gal. aft axle fuel thank.
I could list the whole thing but it's already borring as is.

Is it possible that I may of jarred the sensor in the thank "Loose" or something?
As of today I got 4100 miles on it, and can't get above 250 miles remaining.
P.S. A couple times after a fill-up from a quarter thank, the needle on the dash would take about 10 to 15 miles of driving to show up full.
It's starnge that's why I need your advise.
Thanks

 

I had mine down to 0 and drove another 3 miles or so with it reading 0 the whole way. It went from 15 to 7 in about 1 mile then 3 then 0 within the next mile.

 

i test drove one and when i took it back to the dealer, it had 3 miles left till empty and when i pulled it in the lot it started missing really bad, and that was on level ground, so when you get that low your in trouble

 

I filled up today. 30.5 gallon tank. Computer said 10 miles to go and I was able to put in 29 gallons- keep in mind I can always add 4 more gallons after handle first clicks due to foaming. I got 12.4 MPG hand calculated that tank so I would say the computer was pretty accurate that time.

 

do you guys south of the border have the L/100kms on your info centre? The model I have has Litres and gallons, I am getting 20mpg, (imperial) when I convert 14L/100kms, I haven't messed around with going too low on fuel, when the low light comes on I usually fill up pretty quick....

 

mine will say 50 miles to empty.

 

Not sure where this thread is going, but a little earlier this evening I was running a little low but I wanted to wait for a fuel place that I saw earlier with diesel at $2.81.9 per gallon. My first warning light came up at 50 miles to E. I drove about 10 or 12 miles and then the next warning came up and said 25 miles to E. I pressed on (had about 10 more miles to go for the cheaper diesel. No more warnings. Filled up, it took exactly 34 gallons to fill er up. Computer then showed 530 miles to E.
As to Razberry's question, looks like he's getting a little over 6.2 MPG which is very possible with his configuration and the type of driving in LA. My son has an 08 F250 work truck equipped exactly the same as mine except his is a short bed and he hauls around a 100 gallons of diesel fuel for equipment and misc. tools and he says his gets anywhere from 7 to 8 mpg crawling around in the mountains on gas roads, etc.

 

IMO the gas light is beyond inaccurate! Here is why, I have filled up several times in my truck at 0 miles and the pump will always top at right about 24 gallons. There is no way the light can be correct if its a 30 gallon tank. I have even driven it 20 miles past 0 and had no issues. The last time I put gas in it was right at 0. I put in exactly 3 gallons and re-set trip B. When I started the truck back up, the light remained on and continued displaying 0. I have even seen my light come on when I was well at a 1/8-1/4 tank and could never understand why. All I know is running a diesel out of fuel is the last think you wanna do. But yes the light IMO is way off.

Nick

Nick