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Fuel Economy Help!

Discussion in 'Gen 3 Prius Fuel Economy' started by tolick, Jul 18, 2011.

  1. tolick

    tolick Junior Member

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    Location:
    Chisinau, Moldova(Europe)
    Vehicle:
    2010 Prius
    Model:
    IV
    - Have you read This Thead Yet?
    YES

    - What fuel economy are you getting and how are you determining fuel economy? (trip computer or manual calculations)
    I'm getting 47MPG using trip computer

    - What fuel economy are you expecting and why?
    Over 50MPG as i'm driving in a crowded city almost all the time.

    - What are the approximate outside air temps?
    80-95F last two weeks

    - How long are your trips?
    10-20miles

    How old is your 12v battery? What is the voltage reading of your 12v battery after sitting over night? (Method Here)
    It still cars factory battery (Car have 9300miles ODO). Wasn't able to check voltage till now.

    Have you had your alignment checked? Any pulling or abnormal tire wear?
    No wheels alignment yet. Still all factory tires.

    - How much of it is city vs. highway? Roughly what's the average speed in overall and and of each segment? Is there a lot of stop and go driving?
    80% in the city and 20% off city(i was driving around 45mph out of city)

    - What's the terrain like of your drives? (e.g. flat, gentle hills, steep hills, etc.)
    Most of time have flat roads but i'm driving usually on two-three gente hills in the city. (same situation for roads after the city i was driving)

    - What are your tire pressures?
    210KPA

    - Is your oil overfilled? (i.e. above the full mark on the dipstick)
    No, it is on the middle on the area between full and empty marks

    - Make, model, year, engine and transmission of previous car? (e.g. 08 Honda Civic Si 2.0L 4 cylinder, manual transmission) What did you actually get on the same trips/commute? (Please give us actual numbers, not EPA ratings.)
    2008 Honda Civic Coupe - don't know MPG

    - What region/state are you in? (if you haven't set your location)
    City: Chisinau, Country: Moldova(Europe)

    - How are you trying to drive (e.g. trying to stay in electric only?) and how hard are you braking?
    Trying to drive in using electric engine till get 2 bars and fuel engine automatically starts.

    - What modes are you using, if any? "normal", EV, power, eco?
    always eco mode

    - Are you "warming up" the ICE (internal combustion engine) by letting it idle after powering on?
    NO, it's too warm outside anyway :)

    - Are you driving using D or B mode?
    always D

    - HVAC settings? Are you using the heater, AC, auto mode, etc.? If using auto, what temp is it set to?
    AC always ON in AUto Mode on 78F

    - Are you using the factory tires and wheels? If not, please indicate tire make, model and size (e.g. Goodyear Assurance Fuel Max 185/65R15).
    15" Factory tires and Wheels

    - If reporting a mileage drop, did anything significant change on your car (e.g. accident, hit a curb or big pothole throwing off alignment, oil change/other maintenance/repairs, changed tires or wheels, etc.) or your commute?

    Changed Oil when after car was imported from USA(around one month ago) and used 0W20 Oil changed at toyota delear from Moldova. Also air and oil filter was changed using oem filter i bought from parts.com
     
    #1 tolick, Jul 18, 2011
  2. F8L

    F8L Protecting Habitat & AG Lands

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    I would suggest you stop using the EV button. You are losing efficiency by using battery power exclusively. When the battery runs low you must recharge it using the engine. This is not efficient because you are converting energy multiple times. Each time you convert energy there are losses suffered. Just drive it like a normal car and see if that helps.
     
    #2 F8L, Jul 18, 2011
  3. tolick

    tolick Junior Member

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    Location:
    Chisinau, Moldova(Europe)
    Vehicle:
    2010 Prius
    Model:
    IV
    I was never driving in EV mode. I'm driving always in ECO mode and i'm trying to keep the acceleration slowly to not reach the middle line from the HSI display when ICE engine starts.
     
    #3 tolick, Jul 18, 2011
  4. spiderman

    spiderman wretched

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    Vehicle:
    2010 Prius
    Model:
    II
    Just try to drive it like any other car you have owned and after a couple of weeks see what the results are. Try fairly brisk take offs from the stops (just below power zone). Let the engine run.

    The A/C use is going to hit your FE. I would say your FE is pretty average for the situation.
     
    #4 spiderman, Jul 18, 2011
  5. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
    Staff Member

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    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    I think this is part of what he's talking about. With the addition of the [EV] button, Prius drivers now have two ways to enact EV mode: by driving the car carefully to avoid having the ICE come on and by pressing the [EV] button. The former is more 'natural' whereas the latter is sort of 'forced'.

    One issue I see is that "crowded city" part.
    Unfortunately, sitting stationary drains the battery. It's like electronic idling, just to keep the car on. Many of us have lamented about being stuck in traffic for large stretches of time and watching our state of charge drop the whole time.

    Another issue is the "two bars" part.
    When the battery gets to this point, the power from the ICE is "split" between powering the wheels and recharging the battery. This is amazingly inefficient. It is best to attempt to keep the battery state of charge closer to the 50% mark, preferably a little higher. Now, I think I know what you're thinking right now: how can running the engine more be more efficient than driving on battery. But I'm going to ask that you just take a leap of faith on this one. Others might disagree with me on this one but I would like for you to try and not stretch the electric range as much. It will be frustrating, I know. But I personally suggest that you try it for a week or more and see if your mileage improves.
     
    #5 TonyPSchaefer, Jul 18, 2011
    1 person likes this.
  6. F8L

    F8L Protecting Habitat & AG Lands

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    Tony is very knowledgeable on this subject and achieves very high mpg tanks.
     
    #6 F8L, Jul 18, 2011
  7. tolick

    tolick Junior Member

    Joined:
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    Location:
    Chisinau, Moldova(Europe)
    Vehicle:
    2010 Prius
    Model:
    IV
    Thank you very much TonyPSchaefer for your advice. Very very great post!
    Will come 2nd refill next few days and i'll try your recommendations after that.
     
    #7 tolick, Jul 18, 2011
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