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Very low MPG 2012 Prius V

Discussion in 'Gen 3 Prius Fuel Economy' started by akaGG, Sep 16, 2023.

  1. akaGG

    akaGG New Member

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    Best mpg is 35 around town (driving conservatively). Gasoline engine runs for 2-3 mins on startup and sounds like a low growl. Looking for reasons why it doesn’t switch to EV sooner.

    Had plugs changed, treated gas and oil, cleaned EGR valve (as well as other fuel components). Dealer checked codes but doesn’t seem to know (or care) why MPG is low.
    Any help would be appreciated. Grace
     
    #1 akaGG, Sep 16, 2023
  2. Tideland Prius

    Tideland Prius Moderator of the North
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    The hybrid battery could also be on its way out if the engine is running more often than usual.

    Is the battery meter SOC fluctuating more frequently than before?
     
    #2 Tideland Prius, Sep 17, 2023
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  3. burebista

    burebista Active Member

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    Also take a look at brakes maybe they're drag a bit?
     
    #3 burebista, Sep 17, 2023
  4. ASRDogman

    ASRDogman Senior Member

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    How many miles?
    Did you clean the cooler? And intake manifold?

     
    #4 ASRDogman, Sep 17, 2023
  5. akaGG

    akaGG New Member

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    Thanks for reply. I’ve had a year, so I’m not sure what’s customary, but I think it is up and down quite a bit.

    thanks for the reply. I’ll have someone take a look at the brakes again. Front brakes, two years old, rear brakes, just done by dealership.

    Thanks for the reply. I’ll have to ask the dealership if they check the cooler I believe they did clean intake manifold.

    149000 miles
     
    #5 akaGG, Sep 17, 2023
    Last edited by a moderator: Sep 17, 2023
  6. Tideland Prius

    Tideland Prius Moderator of the North
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    Mmm, with the NiMH, if it's on its way out, it'll typically run down to 2 bars pretty quickly and the engine is forced to run to charge it back up. You may see the SOC rise again when you regen brake but it'll run down again.
     
    #7 Tideland Prius, Sep 17, 2023
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  7. ASRDogman

    ASRDogman Senior Member

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    I'm certain the dealership did NOT clean the cooler. MAYBE replace it...
    Nor did they clean the manifold. I doubt thy did anything with it.

    You can find a used cooler on ebay, or junk yards. Then clean it yourself. And
    have them replace it if you can't do it yourself.
    Same with the intake manifold.

    Thanks for the reply. I’ll have to ask the dealership if they check the cooler I believe they did clean intake manifold.
    149000 miles
     
    #7 ASRDogman, Sep 17, 2023
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  8. nicoj36

    nicoj36 Active Member

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    Try this reset and let us know if it improves your MPG
     
    #8 nicoj36, Sep 17, 2023
  9. Mr. F

    Mr. F Active Member

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    Cleaned in place or off the vehicle?

    Fuel system cleaner poured in the tank can dislodge larger debris which will quickly clog the injectors' finely pored filter baskets. If the baskets are damaged, the debris can lodge themselves in few different places preventing it from ever closing completely, and resulting in a rich mixture for that particular cylinder.
     
    #9 Mr. F, Sep 19, 2023
  10. akaGG

    akaGG New Member

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    Thanks for sharing video. How does steering sensor reset effect MPG?
     
    #10 akaGG, Sep 21, 2023
  11. akaGG

    akaGG New Member

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    Cleaned in place probably. 4 hours for a bunch of work
     
    #11 akaGG, Sep 21, 2023
  12. akaGG

    akaGG New Member

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    Yes, I get a lot of fluctuation in bars. Had purple bars for a day or two but gone now.

    Any recommendations for battery replacement? Is OEM best?
     
    #12 akaGG, Sep 21, 2023
    Last edited by a moderator: Sep 21, 2023
  13. Tideland Prius

    Tideland Prius Moderator of the North
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    The only time I get purple bars is if I run the A/C and idle or if I accelerate hard while the engine is cold. With NiMH batteries, it's rare I get down to 2 bars. It could be on its way out.

    I don't because when ours went, the Gen 4 was about to launch so we took it as an opportunity to upgrade to the Gen 4. At that time, we were quoted CAD 3,000. It's likely the price is higher now due to inflation.

    Depends how long you intend to keep the vehicle. If the rest of the vehicle is in good shape, you could replace it with a new OEM HV battery. This way, the car will operate almost like new and you'll get back mpgs closer to what it was when new.

    The alternative is to buy a refurbished OEM which is cheaper of course. Or even cheaper still, a salvaged battery but with that, you don't know how long the life will be as it'll be a crapshoot unless it's been tested for state of health.
     
    #13 Tideland Prius, Sep 21, 2023
  14. nicoj36

    nicoj36 Active Member

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    It's more than just a steering reset. It also resets ecu and hybrid battery. Also, clean your MAF sensor with CRC cleaner. If you do all three: reset, maf, fuel-treatment. Guaranteed you will gain/restore MPGs.
     
    #14 nicoj36, Sep 21, 2023
  15. Mr. F

    Mr. F Active Member

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    And if you have any dents or peeling paint or cracked glass anywhere on the body, it magically fixes those too. It also self-cleans the EGR circuit, rebuilds a leaking head gasket, and regrows a stolen catalytic converter. This secret trick makes your decade old car look and function just like the day it rolled off the assembly line.
     
    #15 Mr. F, Sep 22, 2023
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  16. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    Soaking in Windex works wonders too.
     
    #16 Mendel Leisk, Sep 22, 2023
  17. akaGG

    akaGG New Member

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    Great info and recommendations. Thanks so much.
     
    #17 akaGG, Sep 22, 2023
  18. nicoj36

    nicoj36 Active Member

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    #18 nicoj36, Sep 22, 2023
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