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Trip Meter vs Energy Graph Average

Discussion in 'Model S: User Interface' started by jvonbokel, Jun 13, 2013.

  1. jvonbokel

    jvonbokel John VonBokel

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    #1 jvonbokel, Jun 13, 2013
    Last edited: Jun 13, 2013
    Lately I've been paying close attention to the Wh/mi number on the "Since Last Charge" trip meter as I hit 5, 15, and 30mi, and I've been comparing it to the Wh/mi average displayed on the Energy Graph at the same time, and there seems to be a disconnect. Does anybody know if this is expected behavior, or why those values don't/shouldn't line up? So far it seems like the trip meter is consistently higher, but only by ~5Wh/mi.
     
  2. Longhorn92

    Longhorn92 MS VIN #10103 (40 kWh)

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    I've noticed the same trend; however, I haven't been as diligent with checking at exactly 5, 15 and 30 miles. The only thing I can think of is, if it has been a while since charging stopped, that the Since Last Charge could be accounting for the vampire losses between when charging stops and driving begins. That would make sense as to why it's higher.
     
  3. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    I've found the "since last charge" (SLC) is more useful than the graph, so I rarely use the graph other than for entertainment. Adding the rated miles left to the SLC miles and comparing that to the rated miles you started out at gives a good indication if you are gaining or losing. That is, if you started out with 240 miles after charging, drove 51 according to the SLC and there are 195 rated miles left. 195 + 51 = 246 so six miles have been gained over the rated range.

    The graph might be more useful if it cover the last ninety miles or so. The last thirty is just too few to get a good handle on the projected range.
     
  4. mknox

    mknox Well-Known Member

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    I have noticed the same thing. I have no explanation as to why.
     
  5. aviators99

    aviators99 Model S - R140

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    I started another thread on this. The main consensus was (and it included some people talking to Tesla, fwiw) that the trip computer does *not* include accessory load.

    In addition to this, I have a gut feeling (that I can't verify) that tells me that the regen is not properly accounted for in the trip computer. I believe it give it way too much weight. I'll have driven over 200 miles at 280Wh/mi and the average has stayed there for nearly the whole time, and then I'll come to a traffic light for the first time and it will drop to 270 almost immediately. Can't be right.
     
  6. jvonbokel

    jvonbokel John VonBokel

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    I'm still trying to keep an eye on this, but I haven't discovered a cause yet. The variation still seems to be really consistent - I don't think I've seen a difference outside the range of 3-5Wh/mi.

    It doesn't make sense to me that the trip meter is omitting anything, because that's the value that's higher for me. Also, I've been monitoring this for a period of time now, including days of varying usage (i.e. sometimes with heavy acceleration and corresponding regen), but without seeing substantial change in the separation of these numbers. My hope was that one day it would be 8-10Wh/mi, and I could pinpoint something different about the usage of the car that day (i.e. heavy accessory load, excessive acceleration).

    One new issue I've discovered through monitoring this is that sometimes the mileage under "Since Last Charge" jumps by 0.2mi. This morning on the way to work I saw it go from 4.9 to 5.1 and also 14.9 to 15.1 (negating my ability to compare at 5mi and 15mi). I can't say for sure if this is an error or just a delay in the update of the display. It's too rare and unpredictable to tell. I think I've seen it 5 times total in about a month.
     
  7. AC1K

    AC1K Member

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    dont mean to bring up a dead thread but it dawned on me that the trip meter and energy graph should not be the same unless you traveled exactly 50kms on the trip and have 50km shown on the graph.

    the graph only represents your short distance interval and trip is from last charge.
     

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