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2013 prius c no codes but reduced mpg's

Discussion in 'Prius c Main Forum' started by elmo, May 26, 2024.

  1. elmo

    elmo Junior Member

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    car has 92k so I'm wanting to hold on to it if possible. thinking reduced mpg's the result of failing hybrid battery. really can't think of anything else though I've decided to go to a dealer here in bradenton fl. for a diagnostic to c what they say.
    as I've been scoping about for a replacement, currently the dealers are at @ $4k for a new(?) hybrid battery. some come with different warranty lengths as well and on the gulf coast I have only about 3 local to me. have read some of the posts about after market vendors who seem to b in general renewing(?) old batteries and hoping they last long enough not to have to deal with warranty issues or, if so, to rope a dope the customer about till he surrenders.
    not sure how to move forward and looking for advise. tia
     
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  2. bisco

    bisco cookie crumbler

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    give tampa hybrids a call. idk if they do c's, but worth asking.

    what was your mileage, and what has it dropped to? a number of things can contribute like tyres, brakes, 12 volt, cooling fan, air filters and etc.
    as for a replacement, reconditioning can be iffy.
     
  3. rjdriver

    rjdriver Active Member

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    If it does turn out to be the hybrid battery, check out Green Bean Battery for a replacement. Current cost for 2013 C is $1724.00 installed, with 3 year unlimited miles warranty. They also offer a lifetime warranty upgrade at additional cost. They do the installation wherever the car is - home, work, beach :).

    Ask the dealer what their warranty is on a replacement battery. I'm pretty sure it's not the same as when the car was new..
     
  4. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Generally speaking a Toyota battery gets you a short warranty that nobody ever needs to use.

    The vegetable-themed ones come with longer warranties but you'll be making claims.

    Decide how much of your time you want to spend on that.
     
  5. elmo

    elmo Junior Member

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    dear bisco
    my mileage has consistently been 55 mpg's. now more like low 40's high
    dear bisco
    mileage was consistently 55 mpg's. now more like low 40's and high 30's. when I drive using staying in the ev mode my mileage also seems to deteriorate. why would you think the 12volt might b impactful. mine is 5ys young of a 7 yr warranty thur the dealer?
     
  6. elmo

    elmo Junior Member

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    thank you rjdriver.
    $1724.00 is much more tolerable than $4k at the dealers and comes with similar warranty parameters. that said, who wants to b in bed with a warranty issue to resolve with combative sellers? green bean seems highly rated and seems to make sense to me. don't understand the 12 volt battery remarks. thought the regular battery was mostly there to start the vehicle and maybe get the computer active? not sure why its mentioned when mpg's decline?
    in any event, thanks for your advise. appreciate..
     
  7. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Your understanding is correct. However, owners of the big-body Prius have found a certain condition where a failed 12v battery can trick the car into working too hard to recharge the battery, which shows up as reduced MPG.

    I haven't heard of this happening in a c.
     
  8. elmo

    elmo Junior Member

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    thanks for the input leadfoot. that's an interesting perspective. doubt the c qualification makes a difference in this situation. why would it? have the vehicle at the dealer for diagnosis. still haven't heard a peep out of them and dealers never inspire my confidence but such is life I suppose
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    New tires? They can drop mpg.

    Also, per @bisco, any recent brake work? Something may be dragging. Or a longstanding lack of brake work.
     
  10. rjdriver

    rjdriver Active Member

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    I wouldn't completely rule out the other battery. A faulty 12v can cause some odd symptoms, even effecting mileage. There's an easy way to check. Turn car on. Hold the CAR button on the dash while turning the headlights on and off 3 times. This will bring up the Service Menu. Press Function Check/Setting, and then choose Vehicle Signal. Your battery voltage will be displayed. If it's less than 12, there could be a problem. Have it professionally checked.
     
  11. elmo

    elmo Junior Member

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    dear rjdriver,
    basic prius c and no car button to press, just your regular ol' car key I'm afraid. still waiting on dealers service to give me a holler.
     
  12. elmo

    elmo Junior Member

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    thanks mendel but no new tires nor recent brake work. did front ones about 10k ago and rear ones checked and still good looking. still waiting on dealer's service dept for a diagnosis. at 11 yrs young, am thinking hybrid most prob even though I only have 92k on the odometer. when I drive on ev alone and avoid using the ice, I don't see mpg improvement. actually they go down slowly. hmmm
     
  13. Mendel Leisk

    Mendel Leisk Senior Member

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    Or just put a volt meter on it, first thing in the morning, car off.

    For more accurate assessment, something like Solar BA9 can test the CCA, a good indicator of the battery's overally health.
     
  14. rjparker

    rjparker Tu Humilde Sirviente

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    Checking the 12v battery is worth the time. An auto supply will do it free or you can buy an acceptable $25 battery tester which can be used on a battery in or out of the car..
    IMG_5218.jpeg

    However it is much more common a failing 12v battery will not Ready your car or the keyless entry won’t work - without impacting mpg. It is a rare 12v battery that still Readys a car but sucks excessive engine / hybrid battery power to keep it charged.

    An old hybrid battery is a common mpg problem.

    Don’t buy a used hybrid battery. You are getting nothing better than your battery with the weakest modules replaced with someone else’s used modules. Your battery will end up in another Prius c or you might get it again as a warranty replacement. By the way they are not as quick on warranty repair as they are when you are buying.
     

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    #14 rjparker, May 29, 2024
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  15. elmo

    elmo Junior Member

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    thanks all for the counsel. but and this is a big butt, the dealer found nothing wrong. so at square one. 12volt battery and hybrid both ok. tires good. maybe a fuel injector cleaning but I lose mpgs even on ev only without ice so am not overly gung ho on finding a gas treatment and have over the yrs never found chemicals would work magically as well.
    so irrespective of no codes showing, I"ll just use it till something shows up. at 38 mpgs about now. not ideal but still better than my subaru and walking I suppose.
     
  16. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Only other thing I could suggest is maybe looking at the air conditioner.

    When a Prius air conditioner loses some refrigerant charge over time, the automatic climate control system will force the compressor to work harder and harder to make up the deficit.

    This uses a lot of energy, showing up as lost MPG. It also (eventually) wears the compressor to death.

    There is no "gas gauge" for refrigerant, so you can't easily tell if you are missing any until it is too late.

    But the point is, if you drive a couple of days with no air conditioning and your MPG is magically like before (or even better than before) then you might have found a cause.
     
  17. elmo

    elmo Junior Member

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    thanks leadfoot, interesting perspective and obviously worth a peek. in florida, its not an easy trial however as temps of late have been in the 100's and its not even summer as yet. it does makes some sense however that after 11 yrs refrigerant might b on the low side of things but it still blows nice and cool. in maryland with kids, etc but will b back at the ranch early next week and will give your perspective a look see. thanks for hanging along with my issue. was very disappointed with the dealer. $100 for nothing basically though they said they would b happy to rotate my tires. am I lucky or what?
     
  18. rjdriver

    rjdriver Active Member

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    Ahh...didn't notice you had a One. Sorry. But it turns out both batteries are fine, so that's a plus. But still a mystery. 38mpg is certainly not normal unless you have a very heavy right foot :) BTW, have you had this car from new?
     
  19. elmo

    elmo Junior Member

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    yes rjdriver and for 11 yrs it has consistently run at 55mpg's and not 38 or low 40's. my foot is light and again if I run on ev alone, I still lose mpg's, at least a tenth every mile or so. don't know how low I can go but like the perspective of leadfoot and the ac connection. other than that I'm still quite flummoxed by almost a 40% reduction in mileage. that's pretty significant and wouldn't you think something or things would clearly present itself as the culprit?
    anxious to get back to florida and run the ol' girl without ac and see what if anything happens?
    thanks rj
     
  20. bisco

    bisco cookie crumbler

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    are you saying you can watch the average mpg drop with the engine off?