DTE calculation

[PRS]

What MPG value does the truck use to calculate Range to Empty? I have noticed that the Range to Empty can change rapidly after unhooking or hooking the trailer. But it doesn't seem to be tied to the Fuel economy screens or the MPG on Trip A or B.

 

[Topzide]

That value is tied to engine load and trans shifting. This is why it will change suddenly after the terrain you've been driving on changes. You can be in head winds, mountains or flat terrain and all have different read outs. If you were able to drive the same way from start to finish of the tank, it would only vary a few tenths. Hope that helps, enjoy that truck!

 

[Ozymandias]

And as a side note to above said, the ECM counts every single injection event and it's volume of fuel used for it. So it really knows how much fuel goes through the injectors. The rest is an algorithm.

 

[AH64ID]

It has it own algorithm that is based on a shorter term mpg readout that trip A/B or the fuel page, and tank volume.

It’s an ok tool if the mileage has been steady and will stay the same the fuel runs out, like on a car. On a truck with varied uses it’s less than useful more often than not.

When I went to the 55 gallon tank on my 18 the DTE because useless, and I haven’t missed it.

 

[Wiredawg]

For me, DTE is much less relevant than the the position of the the fuel gauge needle. I fillup around 1/4 of a tank, regardless of fuel tank capacity. I maintain fuel logs on everything, hand calculated, that usually is close to the mpg lie-meter. My Ram carries 112 gallons (60 gallon aux tank) and my MH 140 gallons (2nd 70 gallon tank), so 1/4 tank leaves a nice reserve. Just another perspective of DTE use, or in my case, minimal use.

 

[sag2]

There was a TDR article a few issues back that covered the DTE and fuel economy calculations on our trucks. Without looking for it I recall it does not use a straight average from the time it was reset, but updates based on the last xx miles of travel. Perhaps someone recalls who wrote it and we can narrow the search down.