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Anemic performance in the mountains

Discussion in 'Prime Care, Maintenance and Troubleshooting' started by srivenkat, Jan 6, 2021.

  1. srivenkat

    srivenkat Active Member

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    Hi All,

    I picked up my new 2021 Prime XLE in Catonsville, MD and while driving it home to Illinois, I noticed the car was struggling to climb in the mountains around Cumberland, MD thru Morganstown, WV. With the accelerator pedal pressed down to be just before entering PWR range, the best it could do was 34MPH in the 55MPH zone. I was quite surprised by this. I did momentarily go into the PWR range but it didn't help matters much. Even trucks were crossing me at 55MPH. Anyone else noticed this kind of (lack of) performance in the mountains?

    I did add Shell gasoline towards the end of the 700 mile trip home but although I ran out of the mountains by that time, the performance on the interstate still seemed to be generally lacking.

    I am almost thinking about taking it into the dealer.

    Thanks in advance for your thoughts on what could be wrong.
     
    #1 srivenkat, Jan 6, 2021
    Last edited: Jan 6, 2021
  2. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Use the entire pedal travel, that is why it is there: for hills.
     
    #2 JimboPalmer, Jan 6, 2021
    Last edited: Jan 6, 2021
  3. john1701a

    john1701a Prius Guru

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    Being apprehensive with the pedal is a common newbie behavior... hence the recommendation: Just Drive It.

    My experience is going 80 mph in the rolling climbs through Wyoming and 70 mph through the Black Hills of South Dakota. Neither was an issue.
     
  4. srivenkat

    srivenkat Active Member

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    Thanks. I would have persisted with PWR and probably would have done the entire pedal travel, but for Toyota's brake-in recommendations for the first 600 miles. In retrospect I probably should have looked for a non-mountainous route. But I am still surprised by the meagre performance to the point I am wondering if what I saw is normal.
     
  5. srivenkat

    srivenkat Active Member

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    No doubt I was trying to be extra cautious during the brake-in phase, but I have been driving the Prius since 2011 and a Prime since 2020 although on flat Illinois lands.
     
  6. ChapmanF

    ChapmanF Senior Member

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    1.If you don't ask for full power, you don't get full power.

    2. Even if you do ask for full power, you get 121 HP. It is a Prius....
     
  7. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    The first rule of brute force is that if it doesn't work, you aren't using enough.

    Mash that pedal flat.
     
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  8. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    I have an odd perspective as my Prius is the second most powerful car I have ever owned. (least powerful was 59 HP in 1977)

    My Subaru Forester had 45 more HP but the AWD added quite a bit of friction that made it seem less powerful.
     
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  9. srivenkat

    srivenkat Active Member

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    IIRC, I was seeing about 2400RPM on the SGII at the time it was doing 34MPH on the 55MPH zone.
     
  10. srivenkat

    srivenkat Active Member

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    Thanks. Do you recall doing a lot of pedal-to-the-metal in those drives?
     
  11. ChapmanF

    ChapmanF Senior Member

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    Have to get to 5200 to be at full power.
     
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  12. dbstoo

    dbstoo Senior Member

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    What you saw is normal. If you take a mustang and only give it 1/2 gas pedal it will bog down on an up hill climb too. You TOLD the car that you only wanted to go 35 MPH.

    I tell newbies that the hybrid gas pedal is NOT connected to the engine. It does not make the engine go faster or slower It is not an accelerator. It's a 'speed pedal' that tells the car that you want to go faster or slower. The car then decides how much power it needs and where to get it.

    The one thing that took me the longest to get used to on my first hybrid was that I could not judge my speed by the sound of the engine.

    Dan
     
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  13. john1701a

    john1701a Prius Guru

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    Yes, when passing trucks at +90 mph.
     
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  14. bisco

    bisco cookie crumbler

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    were you in power mode?

    i feel like my pip is less powerful with mostly engine vs my gen 2, i wonder if that legacy continues?
     
  15. dbstoo

    dbstoo Senior Member

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    For the record... I've taken my prime through hill and dale as well as over mountain ranges and up looooong inclines. No Anemic performance. ***

    Dan
    *** Well, the first day, I expected the acceleration would be the same on the freeway on-ramp as it was on at a traffic light. I had it in eco mode so it accelerated slowly ans smoothly. I still got up to speed well ahead of the end of the on-ramp, but was expecting it to feel as fast as it looked. :)
     
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  16. srivenkat

    srivenkat Active Member

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    Yes, I was in Power mode in hopes that would cause more of the approximately 3% of the remaining charge in the traction battery to be used.
     
  17. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    I don't know that power mode does any specific apportionment of power in a prime. In the regular models, it just remaps the accelerator pedal somewhat, so you don't have to push it quite as far to achieve high demand. The hybrid computer splits the duty however it normally does while responding to the extra demand.

    0% is still 0% and 100% is still 100% but it's got a curve to it- now 50% pedal gives 80% result.

    Looking back to the bigger picture: I'll be blunt- there's just no way that car will climb a hill like that, at speed, with a low traction battery, without that engine joyously singing the song of its people at 5000+rpm.

    And that's fine, even during break-in, at least for short periods.

    If anything, it's of great benefit to cycle between high rpm and low rpm during break-in.

    The car was built with just enough power to handle these mountain highways, but only if you use the entire powerplant- even the loud parts.
     
    #17 Leadfoot J. McCoalroller, Jan 7, 2021
    Last edited: Jan 7, 2021
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  18. srivenkat

    srivenkat Active Member

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    I had heard about the modes simply remapping the pedal response with some AC economy in the Eco mode, but I always had the seat-of-the-pants feeling of instant battery torque when driving in Power mode in my 2010 Prius. I found last evening that what you mentioned about 5000+ RPM is true; I took my "older" 2020 Prime out on the interstate and did the pedal-to-the-metal (that I had done once or twice in my life in my Camry in emergencies) thing, maxing out at 5184 RPM and the car did go from 65 to 90 quickly.

    @2k1Toaster assures in the below relevant post that it's impossible to redline the Prius.

    #6
     
  19. jerrymildred

    jerrymildred Senior Member

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    WOT is WOT, no matter what the mode you have selected. I love ECO mode because, at low speeds in EV, I can accurately modulate the "go pedal" to keep the instantaneous m/kWh bar close to where I want it. PWR mode is way too twitchy at low speeds for that kind of fine control. And if I punch it, the result is the same in all modes.


    Throttle mapping.png
     
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  20. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    This is an important point.

    The system is well managed and has years of debugging done by now. If that car is in READY mode & D gear, nothing you do to the skinny pedal will over-rev the engine.

    Feel confident.
     
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