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Fuel Consumption and Hybrid Battery

Discussion in 'Prius c Fuel Economy' started by Zeeshan85, Aug 10, 2017.

  1. Zeeshan85

    Zeeshan85 Junior Member

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    Hello friends,

    I am first time user of a Hybrid Car and live in Pakistan

    I own a Prius C (Aqua) 2013 Model. I bought it directly from auction in Japan (4.5 Grade Car and 31,000km mileage) which I started using from February 2017.

    I used to get around 22 to 24 km /ltr (88 to 91 km / gallon) in city (normal traffic). Since two weeks the mileage has suddenly dropped. Now I am getting 15 to 17 km / ltr (63 to 65 km / gallon. I have not made any modifications to the car. EV usage before and now is between 48 to 52%. The engine oil Change is due in 500km. The air filter is in average condition not very Good but as per the mechanic will need replacement after a month. tyres are in Average condition. Tyre pressure I keep is 31psi now and before. A/c is used at all times. Not sure how to discrimination my driving style. (all these factors have been same when I was getting good average). Outside temp is around 33 to 35 C (Head Index 45 to 48 degree, 2 weeks back it was 2 to 3 degree lower).

    I made my first trip to another city (total travel distance of 360km, 330km highway and 30km city travel) EV usage 6% average speed 82km / hr (110km/h on highway) and the meter showed average of 21.6 km / ltr average.

    I observed during the travel that battery was continuously charged on highway with 2 bars short of being full. The battery was not getting 100% full and charging continued through out. (reference photo attached). Please guide me on what is causing this sudden drop in average. I am concerned that with 40,000 could my hybrid battery be malfunctioning.

    [​IMG]
     
    #1 Zeeshan85, Aug 10, 2017
    Last edited by a moderator: Aug 10, 2017
  2. Zeeshan85

    Zeeshan85 Junior Member

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  3. bisco

    bisco cookie crumbler

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    welcome!

    has the temperature changed?
     
  4. Zeeshan85

    Zeeshan85 Junior Member

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    Thanks for the quick prompt.

    Tempt has changed only slightly from 33C (Head Index 42C) to 35 36C (Head Index 45 to 48C). Head index increase is due to increase in humidity in the monsoon season.
     
  5. bisco

    bisco cookie crumbler

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    more air conditioning will use more fuel. how is the weather? humidity and rain cause more friction, increasing fuel usage.
     
  6. Zeeshan85

    Zeeshan85 Junior Member

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    Humidity has surely increased alot in past 15 days. From around 30 to 40% to 80 to 100%.

    Is my hybrid battery not charging to full even on highway where it is not being used at all any concerning point?
     
  7. bisco

    bisco cookie crumbler

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    i don't think it's a problem. depending on the type of highway driving, the battery is utilized more than you think. sometimes it will charge to full, but most often, not.

    things to look at if your mileage is down would be tire pressure, air and cabin filters, oil level, binding brakes, etc.
     
  8. Tideland Prius

    Tideland Prius Moderator of the North
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    That is normal. All Toyota hybrids will display 6 bars (out of 8 bars) as their "happy" state. The extra two bars act as a buffer. For example, if you were to go down a steep enough hill or a long enough descent where you are lightly applying the brakes, the extra 2 bars' worth of buffer allows you to recapture the braking force and top up the battery instead of using your brake pads (called friction braking).

    As for the drop in mileage, it could be tire pressure, it could be air temperature/humidity, it could be higher use of A/C. Were you in ECO mode before? now you're not in ECO mode and the A/C is allowed to run higher/faster to cool the interior. Ideally, the battery likes to be in the same temp as you so if it's 33°C, it's better to A/C to ensure that the battery stays cool. Also, check to see if anything is blocking the battery vents (they're located at the base of the rear seat around the footwell)
     
  9. drysider

    drysider Active Member

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    Humidity will increase A/C energy use more than you think. It takes a lot more joules to cool moist air. Physicists talk about enthalpy, engineers about insensible heat.