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Avg. MPG Resets

Discussion in 'Gen 4 Prius Main Forum' started by SusanM, Oct 8, 2016.

  1. SusanM

    SusanM New Member

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    We've been experiencing a strange issue with our MPG average that I wanted to see if any of you have experienced or heard of.

    Three times (seemingly at random times) our overall average MPG has shot up to 199.9, then immediately changed to 20-30, then shifted erratically until it settles into showing the average MPG for the current trip. It then settles into an average from that point until the next time it resets.

    I have calculated what the average should probably show (51) from the EcoDiary, but it's showing 43-47 often instead. The driving doesn't seem to be effected. We just want to be sure it's not indicative of a larger issue. We are also leaving a message with the dealership service center.

    Miles: 835; Bought: 8/24/16

    Thanks,
    Susan
     
  2. Coast Cruiser

    Coast Cruiser Senior Member

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    I think the "Trip-A" indicator is the most simple to use, simple to reset, and easy to see the MPG. That's all I use. I don't go into any of the Eco diaries, charts, graphs, etc. I'm not that serious. :LOL:

    Are you looking at the "from the flag" indicator? I never did like that. It doesn't seem as accurate as the Trip-A.
    And yes, it starts out at 199 mpg, then settles into some kind of average or whatever. I'm not concerned with "daily" or short-trip mpg figures. I try not to get caught up in that stuff... and just drive my Prius like a regular car.

    I go thru a full tank of gas (or half tank) then refuel, and the Trip-A tells me I got 64 overall mpg for that tank. I'm good with that. Simple. Easy. I smile. Get back in and just drive... ;)
     
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  3. Gen 2 Tom

    Gen 2 Tom Active Member

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    Coast, if I understand, you use trip A odometer. Reset it when you refill and you will get a new average displayed for A. And non of the other mileage calculations are disturbed. I'll have to take a look at that. This being my second Prius, I just drive them leaving the MPA average showing the cars total.
     
  4. Coast Cruiser

    Coast Cruiser Senior Member

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    Yes, the Trip-A odometer/mpg display is easiest for me. Reset it to zero at fill-up, and drive off. And within just a few miles the MPG display will show 62 to 64. That seems to be my normal, steady average.

    My hand calculations are very close to that; maybe only 1 or 2 mpg less. But I don't even hand calculate anymore. I'm very happy with anything over 40! :D
     
  5. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    I wouldn't expend too much effort on the in-car displays of mpg:

    1. They're inaccurate, apparently intentionally exaggerating the mpg. With fourth gen the bs factor appears to be around 5%.

    2. All the records the car keeps are volatile, disappear the moment the 12 volt battery is disconnected.

    To track mpg I'd suggest to start a log, just pen-and-paper, or a spreadsheet, and log tanks. There's several online sites that'll help track mpg too. Still, I'd rely on a personal log, websites come-n-go.
     
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  6. Coast Cruiser

    Coast Cruiser Senior Member

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    Mendel, I like the pencil and paper suggestion. That's what I use. But my mpg display has been pretty accurate.

    I don't know why, and it still amazes me, but I get higher mpg when I drive in the PWR mode.

    My gas mileage goes down when I change to ECO mode. I just don't like how it changes the feel of the gas pedal, makes it harder to press, and I don't like the way ECO restricts the air conditioning.

    My mpg falls 4 miles per gallon when I switch back to ECO mode. I think it's just a gimmick. But I don't want to sound snarky or offend people who use that mode religiously. I go with what works best for my car... it likes PWR.:D
     
  7. Coast Cruiser

    Coast Cruiser Senior Member

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    And why does Toyota create three different "driving modes" in the first place. Apparently, the three modes do not change the engine performance or settings, all it does is change the tension of the gas pedal.
     
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  8. kithmo

    kithmo Couch Potato

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    Sounds normal to me, the journey average mpg reading (from start up) starts at 199.9 mpg in electric, then drops low when the engine starts and it is cold (mine drops to around 35-40), then creeps up as the engine warms up. Trips A and B tend to be reset when the engine is warm (at the gas station) so don't behave the same, unless the trip is reset from cold, say at the beginning of the day.
     
  9. eman08

    eman08 Active Member

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    I get 76 to 92 MPGs all the time every time I fill up and reset esp when I'm hyper miling, it will stay in the 70s and 60s for awhile and then slowly drop to the 50s. It stays in the 50s each time I fill up. I get an average around 50-58 MPG per tank by hand with a 2nd gen Prius.

    Posted via the PriusChat mobile app.
     
  10. Coast Cruiser

    Coast Cruiser Senior Member

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    I sure hope we don't have to be concerned about temperatures, and whether the engine is warm or not, and what time of day we reset the trip buttons,... Is it just me, or is that pretty darn ridiculous? That seems way overly complicated to me. If that's truly the case, then the heck with it.

    We should quit looking at all those silly displays, and just do the old pencil and paper thing. Write down the number of miles I traveled, and divide it by the number of gallons I put in! Easy. Done. Go get a cheeseburger.

    (OK, I would actually use a calculator. :LOL: My opinion is only worth two cents, but the only gas mileage that really matters, is how many mpg we get from a full tank. Prius owners seem to really want to complicate things, checking their mpg on a short trip to the grocery store 5 miles away! We are not that bored, are we???)
     
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  11. alanclarkeau

    alanclarkeau Senior Member

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    I agree - I only bother looking if it's a longer trip - at least 25km. Short trips are so variable (my grocery store is 1.2km away) depends on whether it starts in EV or if it waits nearly 1km to do so makes a mockery of any attempt to compare.

    I used to keep a pocket notepad in the car for fuel fillups (from 1974 till about 2000), then went to a spreadsheet. I'm now using FUELLY app too.
     
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  12. bisco

    bisco cookie crumbler

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    i still use the note pad.:oops:
     
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  13. Coast Cruiser

    Coast Cruiser Senior Member

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    Nothing wrong with that. Simple and easy.

    And people keep saying the displays are inaccurate. So I guess hand calculations are better? I have gotten so comfortable with the car now, and I'm so confident that it will get great gas mileage, I'm not even doing the hand calculations anymore.:ROFLMAO: I just gas it, and drive it. (a non-typical Prius owner. :confused:)
     
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  14. bisco

    bisco cookie crumbler

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    agree, i don't even know why i bother anymore, it's always the same.
     
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  15. Coast Cruiser

    Coast Cruiser Senior Member

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    Me too, bisco. It rarely varies, unless I'm on steep hills or something. The overall mpg has been fantastic and I'm very happy with the Prius. (Who cares if I have water and goldfish in the headlights! :LOL:)
     
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  16. kithmo

    kithmo Couch Potato

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    :whistle: So I take it you two have turned off the mpg displays ?
     
  17. RCO

    RCO Senior Member

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  18. Coast Cruiser

    Coast Cruiser Senior Member

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    Sometimes I do. All blank! And I put the Compass up on the small center screen (for lack of something better) I get rid of all those silly "Eco things."

    I make the dash look like my old Camry was... just the speedometer and the gas guage! MPG's were a mystery in that car. :LOL:

    ***How come when people buy a Prius, they become all weird and obsessive about gas mileage?!?
    I thought the whole purpose of owning a Prius, is to NOT be concerned about gas mileage! NOT be worried about MPG! NOT having to be looking at it all the time!

    You already KNOW a Prius is going to get good gas mileage. Right? Why do some guys gotta check the MPG's every 6 FEET!? :ROFLMAO: :confused:

    Just get in it, and drive, baby! :D


    (Whew! That was an emotional post. I need a cheeseburger.)
     
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  19. Coast Cruiser

    Coast Cruiser Senior Member

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    What happen to Susan M?

    We scare her off?????
     
  20. Coast Cruiser

    Coast Cruiser Senior Member

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    Kithmo, do you have cheeseburgers in the UK?

    Pizza?

    Hot Dogs?

    Burritos?

    What is the favorite food in the UK? :)