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Would someone please explain this?

Discussion in 'Gen 4 Prius Fuel Economy' started by PriusRos, Mar 15, 2016.

  1. PriusRos

    PriusRos A Fairly Senior Member - 2016 Prius Owner

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    Trip History screen: How can Average be 54.5mpg and the Best be 14.1mpg? Is the decimal point in the wrong place or something? What does the Trip HIstory refer to? TripHistory.jpg
     
  2. krmcg

    krmcg Lowered Blizzard Pearl Beauty

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    Best is history only, not current. If you beat the best it will change when you update.
     
  3. PriusRos

    PriusRos A Fairly Senior Member - 2016 Prius Owner

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    But how can Best be lower than Average and how can it only be 14.1? This screen hasn't updated since I got the car. What is it the history of?
     
  4. JohnF

    JohnF Active Member

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    Best is probably short for "Previous Best" and the Average probably is short for "Average for this segment". There isn't much room on the screen so they shortened it. I agree it is cryptic and confusing. I never bother to look at that screen because it just confuses me.
    The 14.1 could be several things. Most likely the car was sitting while the techs were working on it, and the gas engine kicked on and off without going anywhere. Another possibility is that the car was being moved around very short distances while cold, so it never warmed up. Gas consumption can be shockingly high when a car first starts from cold. Much lower consumption once it has run a short distances gradually averages this out.
     
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  5. pakitt

    pakitt Senior Member

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    It all depends on which time periods the 2 values are calculated. The user's manual has possibly more information about that.
    If the average is "since you bought the car" and best is related to the last x trips since your tank, they will differ, a lot.
    If you fuelled up the car and the Best resets, as I think the new Prius does now, and you had only 1-2 very short trips, it might be that the best is reall 14.1, because another one was maybe 9.
    I would say the best is to check the user's manual and make a reset of all counters after fuelling up to see how the behavior of the counter really is.
    I wish I had my Gen4 to help you more with that.
     
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  6. krmcg

    krmcg Lowered Blizzard Pearl Beauty

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    Don't reset all of the trip counters! Each one has it's value. For me, I have "B" as lifetime statistics. "A", I "update" for each tank.
     
  7. pakitt

    pakitt Senior Member

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    The Gen4 has an "ODO" average fuel consumption - to reset it you need to select it and then reset it by pressing Trip for some time. Page 110 of the user manual.
    Trip A/B are also still there, and new is the "Mileage since hybrid system was started", which is automatically reset each time the hybrid system goes through a on/off cycle.
    So what I meant, is to reset the A and B trips possibly at the next fuel up and see what happens.
    I suppose what is shown in the dashboard smaller LCD screens is the same as what shown in the main big LCD in the console...
     
  8. PriusRos

    PriusRos A Fairly Senior Member - 2016 Prius Owner

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    Thanks for all the responses but I still can't figure out that screen. I reset A when I fill up and use B for actual trips, such as my daily commute. I've filled up once since I bought it. It did about 550 miles and I put in just over 10 gallons. Very happy with that result compared with the 2010 Prius. I don't think "Best" updates by itself - you have to press Update. It did change to something more realistic but I still don't understand what "best" it was using. It's obvious that "Average" and "Best" can't be measuring the same interval or trip because mathematically Best cannot be less than Average. I know I have to study the manuals - but they aren't the most readable of books and I can never find what I'm looking for!

    The other figure that seems way off is the Cruising Range. On a full tank, it shows something over 800 miles. That would work out to about 70 mpg -- and none of my averages have been that high!

    BTW, Merged, "Best" did not reset when I reset the trip odometer, only when i pressed the Update button.
     
  9. ATHiker

    ATHiker Senior Member

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    Not sure if this will make sense.

    I was screwing around on the big screen and hit the update button just before making a short trip down my street in EV mode.

    Over that very short distance my MPG was ridiculously high -- 90 mpg or something like that. Cool-- I wanted to see a big number for my "best" even if I was cheating.

    I hit the update button again at the end of my street and the 90 MPG sticks.

    Now that is great if I want to show off but I soon come to my senses and realize having contrived number is just stupid.

    So I then hit the clear button up top on the big screen and basicaly start over. Or so I think.

    So now that I ha returned to my sense, I just hit the reset button when I fill tank. If my MPG for the latest tank is "Best" the new number will be registered. If not, the "Best" remains unchanged.

    Prety good.

    I kind of screwed up, however. Had I not felt the need to hit that clear button, I could have had my lifetime MPG show up on the same line as my lifetime odometer -- and have that lifetime span also sync up wth the screen that shows EV% and avg speed since day one. Oh well.
     
  10. krmcg

    krmcg Lowered Blizzard Pearl Beauty

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    I "reset" when I fill the tank. Keeps it nice and simple.
     
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  11. ETP

    ETP 2021 Prime(Limit),24 Venza Limit,B52-D,G,F,H

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    Ditto, reset both every time since sometimes I will use the other as a data point for specific segments.