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Pumping the Accelerator

Discussion in 'Gen 2 Prius Technical Discussion' started by PaulAA, Nov 16, 2008.

  1. PaulAA

    PaulAA New Member

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    I am sorry to say that my wife tends to pump the accelerator while driving the car, whether in heavy traffic, where it can be unavoidable, but also on normal highways and local streets. [A probable related issue is her aversion to the cruise control].

    Of course, this causes the engine to cycle on and off MANY times per mile, and my question is are we thus going to see an early failure of the motor that is used to start the engine so frequently?

    Thanks.
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Hi Paul,

    MG1 within the transaxle is the motor generator that among other things is responsible for starting the gasoline engine. If you had instrumentation that could read MG1 RPM, you would note that it will zoom back and forth at relatively high positive and negative RPM as needed based upon vehicle speed and driver request for power. The 2G transaxle is quite reliable, don't worry about an early failure.

    <In case this is an issue affecting your domestic tranquility, it's not worth it to fight about the issue with "she who must be obeyed">
     
  3. darelldd

    darelldd Prius is our Gas Guzzler

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    Early failure is not a concern. Wasted energy and just poor driving habits in general are the bigger issues.
     
  4. firepa63

    firepa63 Former Prius Owner

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    Maybe she is trying to practice Pulse & Glide...
     
  5. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    Paul, in the event that you are trying to convince her to stop:

    Pumping the accelerator on the Prius is not suggested and should be avoided because it forces the engine to quickly cycle on thus placing undue wear on the transaxle.

    There. You can now tell her that you read it on PriusChat.

    (you're welcome)
     
  6. richard schumacher

    richard schumacher shortbus driver

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    What does she intend to do by pumping the pedal?
     
  7. qbee42

    qbee42 My other car is a boat

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    Inflate the tires for better mileage.

    Tom
     
  8. Qlara

    Qlara New Member

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    Pumping the gas padel is always bad habit on driving any cars......Hybrid or Regular.

    Why does she like to do this? (Is it really a Pumping action? Or just heavy-foot?)
     
  9. jayman

    jayman Senior Member

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    Oy

    (Sound of open palm smacking my forehead)
     
  10. Bob64

    Bob64 Sapphire of the Blue Sky

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    I tend to resort to what I believe is pumping the pedal for short 2-7 second bursts (or less) during traffic to avoid draining down the battery. Should I "ev" mode it instead if it damages the transaxel?
     
  11. PaulAA

    PaulAA New Member

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    and also in response to:
    Originally Posted by richard schumacher
    What does she intend to do by pumping the pedal?

    It's more like a light cycling on and off, simply due to a concern of getting too close to traffic ahead or just going too fast for conditions, simply because of having sped up a little too much, and then having to speed up again [and then repeat].
     
  12. richard schumacher

    richard schumacher shortbus driver

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    Oh: she lurches forward, stops, repeats. That's just ordinary bad driving technique. It won't hurt anything in a Prius except MPGs, and maybe wear down the brake pads and front tires a little faster than they would otherwise. The more constant she can keep the speed the better fuel economy she'll get.
     
  13. richard schumacher

    richard schumacher shortbus driver

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    What you're doing won't hurt the car, but it's useless. When a Prius is ON and *not* in Neutral it maintains the battery charge all by itself.
     
  14. hill

    hill High Fiber Member

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    have her put it in neutral at red lights & have her pump 'till her heart's content ... it'll help get it out of her system. :^)
     
  15. subarutoo

    subarutoo New Member

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    The more you pump the throttle, the more you have to pump the gas.
     
  16. bwilson4web

    bwilson4web BMW i3 and Model 3

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    I was in DC June 23 headed back home to Alabama and remember leaving at 3:00 PM and the rush hour traffic. What you are describing is almost exactly what I experienced on I-66 and later when I took the Gainsville turnoff to Warrenton. I saw the same pattern in all DC 'rush hour' traffic. Everyone was jocking for position with one exception.

    Any truck had a quiet space behind them and the DC area drivers would not dart into that space between my Prius and the truck. When I was behind ordinary passenger traffic, any safety gap was treated as an open space and fair game for a cut-in. Behind the truck, I could not see anything in front but I could travel with a following safety gap and still make good progress.

    Does your wife do the same when there is no traffic around, say on the weekend? If so, I would suggest she drive with a little larger following distance. Now making such a suggestion to a wife is another problem having nothing to do with technology or technique ... it requires ... guile.

    Bob Wilson
    ps. Married 31 years.
     
  17. qbee42

    qbee42 My other car is a boat

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    It's a form of "bang-bang" control, where there are only two control outputs: on and off. Household thermostats are a good example. The house gets to warm, the furnace turns off. The house gets too cold, the furnace turns on. It "bangs" from one extreme to the other, as in a damper banging open and banging closed: bang-bang.

    You need to get the PID control option for your wife. :rolleyes: Actually, humans use as much feed-forward control as feed-back, but let's not get picky.

    Tom
     
  18. jayman

    jayman Senior Member

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  19. 9G-man

    9G-man Senior Member

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    I knew a guy like that in high school. He could not hold a steady speed with the gas pedal. He had to be either accelerating or decelerating, foot on the gas or foot off.
    It was the most annoying thing I had ever experienced.

    25 years later

    I got invited to a UGA game a few weeks ago by a friend, he drove the same way. Unable to hold a steady speed. I just don't get it, what is so hard about maintaining a steady speed with small throttle adjustment....
     
  20. abq sfr

    abq sfr New Member

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    I saw some medicine on a tv ad that is supposed to fix that. It's for Restless Leg Syndrome. You might have her try it. :rolleyes: