Fuel and Distance to empty
 

So for last year and 1/2 when I fill up my display would say 410 miles to E.
Then in April on trip to Dutch John Utah, from LA.
It started to say 390 to E, Well! what caused this?
Then On trip to Tahoe last week I filled up and it said 460!!!!! to E.


How does this truck calculate this??:confused::confused::confused::confused::con fused:
:):)
Mark F.

Re: Fuel and Distance to empty
 

What I have seen over and over is how the MTE makes corrections. Example, my '09 FEH has a maximum MTE of 699 miles after fill-up. All my tanks exceed 699 miles and my last tank was 884 miles. Adjustments increasing the amount of MTE start at just below 3/4 of a tank where my Trip OD added to the adjusted MTE start to add to over 699 miles. I was well over 800 miles on that tank and still was not at 0 MTE because of the corrections the computer made. Once I hit 0 MTE, the computer stops adjustments and I rely on my own knowledge of the amount of .8 gallons left in my tank and my average MPG till I need to fill-up. I never run out of gas in my '09 FEH now that I determined the gas left at 0 MTE.

In your case Mark, I don't know where your mileage is on a tank but you can bet your MTE at fill-up is calculated by your average over the past 50 miles. I say 50 miles because that is where the countdown begins at the 50 MTE warning. I think the computer takes the prior 50 miles to compute your last 50 miles as one important factor. The other important factor is your average MPG from the distance you reset your Econ gauge.

GaryG

Re: Fuel and Distance to empty
 

Thanks Gary.

I too was wondering how the MTE calculation and adjustments are made.

Re: Fuel and Distance to empty
 

I have just crossed the magic 100 mark and have a couple of observations.

1st - the FEH seems far more sensitive to altitude than any car I've owned. Simply, as altitude goes up mileage goes up.

2nd - my gut tells me and after some specific observations that the average mileage used by the computer is around the past 80 miles. For example on a recent trip into Yellowstone National Park I fueled up in Jackson and went on into YNP. The altitude was mostly increasing along the way. At about 80 miles since fillup the MTE jumped from 4xx to 5xx.

I then paid more attention. Inside YNP, where the speed limits are 25-45 mph I noted that as a result of the frequent ICE off operation that the MTE was increasing even more. Ultimately I achieved a sum of MTE plus trip Odometer of around 650+ during the time I was inside the park.

As I came down in altitude on leaving YNP the mileage began to come down again.

3rd - I've noted that the software knows how full the gas tank is (of course) even if you fill up the filler neck and if you fill it really slowly you can put another 2 1/2 gallons in the tank (after the fill nozzle cutoff clunk). So how does the software know when you fill it tippy top full? Don't have a clue but it'll show up on the MTE calculation.

Bottom line for you: part of the issue is altitude. Second if you're traveling and filling the tank a bit fuller, it knows it. Finally, you did a lot of climbing out of LA up into Utah. That caused a hit on mileage that was recovered to some extent on descending into the Utah basin.