To me, it would make sense for the computer to track/estimate the fuel consumed based on the injection rates. the truck knows roughly how much fuel it's injecting as it runs, so I'd figure that would give an accurate assessment. yes, you still have the remaining fuel in the rails, lines, etc, but I'd imagine that really wouldn't total up to be that much.

 

I'm in the middle of a vacation driving from Florida to Maryland. I have driven almost 2000 miles and am averaging 19.7 mpg. The drive up I was loaded with 2 heavy adults and 2 kids, and probably 1000 pounds of luggage and christmas gifts in the bed.

5.0 supercrew 6.5' bed 4x2 with 3.31 rear. I do have a fiberglass topper (truck cap) too. The whole drive up I was running the air conditioner too.

 

I don't think any car manufacturer are too concerned about extremely accurate measurements. For the longest times the fuel gauge was just a rough estimate and if you brake or accelerate hard you could watch the needle move. Heck, I've looked at the gauge of a relatively newer car, turned the car off then on again and the gauge showed a different level.

 

Everyday I drive to work and my truck says I get about 21 mpg.. Except when I fill up at the pump that doesn't seem to be the case.
I fill up at the same place every time and I drive the same route each day of the week. The drive is 25 miles and about 21 miles are highway and I only hit 4 stop lights each way. I have the start-stop function (sometimes annoying) which shuts down the truck at each light.
So I don't spend much time idling burning gas but I still seem to fill up 1 gallon more than my fuel used thinks I burned... Now I fill up on average around 15-16 gallons each time and go 21 mpg..315-326 miles. But I put an extra gallon of gas.. Taking my mpg to about 19.7..thoughts?

 

You may not be doing the math right.

Fill up and reset one of the odometers. Next fillup, divide the odometer reading by the gallons you put in.

 

Mine is right on the mark on the two fill ups I've done.

 

Mine is dead on the mark for the first 2 fill ups.

 

Delete

 

I've noticed on my 13 it depends on what gas station I fill up at, there's 2 stations I use regularly. The one is a Shell station and the pump there is consistently 2 gallons above what the truck says. The other is a Marathon and it's consistently .5 gallons above what the truck says.

 

So far two fill ups on my '16 ecoboost. First tank the truck's computer was 1.5 mpg higher than calculated. Second tank the computer was .8 mpg higher than calculated. I have the 36 gallon tank. On my '15 SD the gallons used was always within about .2 to .4 of actual.

Also if you don't know Ford removed the "gallons used" from the display for the '16 models. I assume because it is so inaccurate.

 

My 2015 XLT SCREW with 5.0, 3.73 gears, and 36 gallon tank is consistently off by 1.5 gallons every fill up since new. My dealer spoke to Ford about it and they replied that the Gal Used readout is calibrated for the 23 gallon tank. Up to this point, Ford has not done anything to address this. I have an open case with Customer Care...nothing has happened in two weeks so far.

So frustrating.

Mo Power

 

It can't be fixed and was removed from the 2016 models, as stated above. If they could fix it, they would have left it on the trucks.

 

I just had my 2015 f150 ecoboost 2.7 in the dealer for the same frustrating issue. I am 10 % off also, always putting in 22 gallons when the dash says 20. Dealer had no answer and said computer normal.

 

Your better off, my 23 gallon is off 10%

 

Did anyone ever find a fix for this? My 2015 f-150 is still reading incorrect.