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    xvs New Member

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    Location:
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    Your Vehicle Year:
    2010 Prius
    Model:
    II
    I've noticed that my new 2010 Prius engine seems to be working WAY too hard trying to accelerate while going up a reasonably steep grade.

    I have to basically floor it to get it to increase in speed at all, and it sounds like it's revving at really big RPMs.

    Is this normal behavior? Once it gets going at a particular speed it seems to be able to hold it fairly well, but this is worrying me.

    The battery is at more than 1/2 charge while this is occurring, so it's not related to charge issues.

    Any help/feedback would be appreciated.
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    ken1784 SuperMID designer

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    2010 Prius
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    It's very normal Prius eCVT behavior.

    Ken@Japan
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    wvgasguy New Member

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    Location:
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    Your Vehicle Year:
    2010 Prius
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    V

    Was your last vehicle a small 4 cyl? Also with no "kick down" as in a traditional transmission, the power splitting device during heavy acceleration does cause the engine to generate a little more noise than I first expected. I noticed it in my TCH and even my HH (which does have a V6 and plenty of power). However I seldom use that power.
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    Mike Dimmick Active Member

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    Other Hybrid
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    My last car was a 1.6 litre Ford Focus. The Prius engine noise is consistent with the higher revs necessary to develop power with a small engine. While the raw displacement of the new engine is higher than that, the effective displacement is reduced by the Atkinson cycle and it behaves like a smaller engine.

    If you're coming from an oversized engine, it will rev higher than your last car in the rare situations - like accelerating uphill - where you actually need the power.
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    The Electric Me Go Speed Go!

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    2013 Prius
    Model:
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    This is a hard problem to diagnose given a written statement and online. It's certainly not outside the realm of imaginability that it is "normal" behavior BUT the only way to know for sure would be to drive a different 2010 Prius up the same hill. If you got a similar sound and feel then you'd know your Prius is behaving like any Prius.

    Since I see you live in San Francisco, being sure your automobile is handling inclines "normally" is probably important. I'd wait until inventories increase, go to the dealer and express your concerns, they might let you "test drive" a different Prius just so you can determine whether you have a problem or not.
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    qbee42 My other car is a boat

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    This is normal behavior for a Prius. The speed of the engine is unrelated to the speed of the car. The eCVT allows the Prius to run the engine at the best speed for any given load. In the case of going up a hill, it takes a lot of power.

    Another thing that creates this sense of a racing engine is lack of soundproofing. While the 2010 is better in this department, it still has little soundproofing when compared to a heavier car. The Prius is quiet because it normally doesn't make much noise, not because of great insulation. When the engine tacks up, you can hear it.

    As for the engine running at high speed, Prius engines never run at high speed. They live a pretty easy life for an ICE.

    Lastly, as mentioned above, the Prius can suffer failures that will cause the engine to tack up. Usually they are related to the HV battery, which means it is highly unlikely in a new Prius.

    Tom
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    patsparks An Aussie perspective

    Member Since:
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    I know what is wrong.
    You should have a Dragon Force CD in the CD player, cranked up loud. The engine noise will be a distant memory before long.
    (your musical preference may vary)

    It's all good, you will get used to it. The computer is letting the ICE spin because it is more efficient than lugging up the hill.
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    royrose Member

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    Location:
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    Your Vehicle Year:
    2010 Prius
    Model:
    IV
    You are both mostly right right but not quite.

    Because of the fuel efficient Atkinson Cycle, the engine doesn't put out as much power per revolution as a normal engine and therefore is not working as hard as rpm might indicate.

    The engine does, however, rev quite high when accelerating up hill. I have a scangauge and have seen the rpm go over 5,000 briefly. The power splitting device sends some of that power directly to the wheels and some to generate electricity to power the MG2 to add torque to get you up the hill. Once up the hill the rpm will drop quickly, maybe even to zero depending on your speed.

    I believe that your car is operating normally.

    XVS: You might enjoy having a Scangauge. As a new Prius owner, I have found it quite educational. I monitor RPM and coolant temp. That tells me exactly what the ICE is doing in various situations including when it reaches warm up. It reassures me that the engine is not overheating when working hard.
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    Fred Hiltz New Member

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    Location:
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    Your Vehicle Year:
    2010 Prius
    Model:
    II
    With no more evidence than your anecdote to go on, I'd say the replies above are correct.

    In addition, see http://priuschat.com/forums/gen-iii-2010-prius-main-forum/65615-2010-prius-models-louder-why.html, where Wayne writes, "If you're referring to exhaust noise, that is true on the highway or heavy acceleration. The Gen III Prius has a valve in the muffler and at higher engine RPM's it opens and allows a more direct path for the exhaust to exit to reduce back pressure. This of course means less muffling of noise."

    Fred
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    qbee42 My other car is a boat

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    I beg to differ. There is nothing wrong with my explanation. Your explanation does not contradict mine in any fashion. It does add more information, which is useful.

    Btw, 5,000 RPM is not very high for an engine of this size. My 1.5 l Honda CRX engine had a redline of about 8,500 RPM - 70% more than what you see on with the Prius. The Prius engine leads an easy life.

    Tom
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    edthefox5 Senior Member

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    Location:
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    Your Vehicle Year:
    2007 Prius
    Model:
    Two

    HI,
    May I suggest you buy a Scangauage here at the Priuschat Shop. Its inexpensive, will help you get better gas mileage and has a tach in it that you can reference too and really see how hard the engine is working compared to how hard you perceive it to be working as Tom suggests given the cars somewhat lack of sound insulation. Most of us own one and it can be used in any OBDII car.
    Its got a temp gauge in it can pull CEL codes etc and all kinds of useful info. Plus purchasing it here supports this great site. It can be found on the top of the page in orange "Shop".
    Good Luck!
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    royrose Member

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    Location:
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    2010 Prius
    Model:
    IV
    OK, I guess I was comparing the Prius to our Murano that has a (conventional) CVT and doesn't seem to get near 5000. I agree that we basically agree!
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    BoBraxton New Member

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    Although I was not surprised at the report of noise (I drive a 2005) I just learned something important: "more direct path for the exhaust to exit to reduce back pressure"

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