Know there have been several discussions about incorrect gallons used on the trip computer, but I found this to be a little amusing. I have the 2.7 with a 36 gallon tank and 3.73 gears if anyone is wondering.

Miles driven: 516
MPG: 19.1
Gallons used: 27
DTE: 91

Does that mean I can really go another 172 miles?
OR
Does that mean I'm only getting 10 MPG with the remainder of my tank?

I REALLY think it means I actually used 30 gallons and am getting around 17 MPG.

I guess we'll see on the next fill up. :-/

 

Distance to empty is probably not to "empty" (i.e. bone dry) but rather distance to reserve which is usually 4-5 gallons left when the fuel light comes on.

 

have you verified the data using the old fashioned method

 

If I really had 9 gallons left I would be a 1/4 of a tank. I'm below 1/8th.
I understand your approach and theirs to leaving some reserve but the that's not the issue here.

Bottom line is gallons used is way off and it makes you feel like you're getting amazing mileage until you do the math.

 

Yes, the gallons used has been way off every time. My overall calculated average is 17.2. The worst the truck has ever said was around 18. I'll update the thread when I fill up next.

 

My gallons used counter is consistently 5-6% low at every fill-up. My miles to empty seems to be accurate (scary, most build in some cushion), based on what I actually pump into the truck.

 

Ford uses the VW method...

 

Do you remote start the truck frequently?

If so it doesn't count that usage. Gallons used I'm pretty sure is just a function of multiplying the fuel pump GPH rating against the time since you reset that screen. I can't imagine they have a more accurate way of keeping up with real time fuel pump output.

I prefer to stick with the DTE number and my avg. MPG. In your case, it says you got 19.1 avg mpg, with 91 mi left, meaning you have (91/19.1) = ~4.76 gallons left in the tank, which much more closely aligns with the 1/8 you're seeing on the gauge accounting for a little error.

 

My truck on E will only take about 32 gallons. The gauge reading is based on level without including whatever amount they decided to include as a reserve.

As for the gallons used and mpg that it displays, in the summer mine is fairly close, the colder it gets the farther off it is. My conclusion is that it does not account for any fuel used while in park as I tend to warm up my truck in the winter and sit at the end of the driveway waiting for the bus with my daughter more often on cold or rainy days.

 

This has been discussed quite a few times as you noted. DTE is calculated on the last 500 miles you've driven AND the fuel sensed in the tank (NOT on gallons used). Go park your truck on a steep hill with the nose up and let it run for a while and watch it adjust. Then reverse it and park it on a steep hill with the nose down and do the same. You'll see a huge disparity in DTE.

If you want a relatively accurate DTE, which does NOT include the reserve, drive it on level ground for a period of time and it will be more accurate.

At 91 DTE and 19.1 MPG, that's 4.8 gallons left. 27 + 4.8 = ~32. That's almost right on not counting the reserve.

I found the gallons used, just like the MPG, to be close enough. I am within 0.5 to 1 gallon on gallons used as well as on MPG by hand calculation.

Ford, like most manufacturers, knows that most consumers are stupid and will drive until they run out of fuel and also overheat the fuel pump that's sitting in the fuel on most vehicles. So they try to account for stupidity, then we complain that they did so.