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Engine Runs a Lot?

Discussion in 'Gen 2 Prius Fuel Economy' started by mcontrols, Jun 6, 2007.

  1. mcontrols

    mcontrols New Member

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    It seems to me that my engine runs a lot more that it should or needs to. When stopped at a light etc., I am on full battery. However, when I accelerate from a full stop I go no more than 10 feet and the gas engine kicks on. I am not accelerating very hard either.

    I installed the EV Kit last year and it works very well. The engine does not start if I'm in EV mode unless I accelerate hard, exceed 33mph, or the battery gets too low. But when I'm in normal driving mode it just seems to me that the gas engine runs too much. I'm getting 44.5 to 46 mpg so I guess it can't be too bad but I feel I should get better. My wife drives the car 99% of the time and she is 125 lbs, and does not haul anything in the car. When I drive it I will be on level ground driving between 35 and 45 mph and the engine and with the electric motor will be on. I would think this would be prime time to be on full battery. Am I wrong?

    I have the car serviced by the local dealer and they say everything is fine. Comments?

    Thanks,

    MC
     
    #1 mcontrols, Jun 6, 2007
  2. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    Hmmm.
    Everything sounds right. I can only assume that you are working to feather the pedal when coasting to invoke the stealth. Without experiencing it, there's not much I can add.

    As for the acceleration, It doesn't really surprise me that the engine kicks on. But once you reach a cruising speed, you're right in that you should be able to stealth on full-out battery.
     
    #2 TonyPSchaefer, Jun 6, 2007
  3. efusco

    efusco Moderator Emeritus
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    Common misunderstanding that's unfortunately caused or exacerbated by Toyota and the Press. While the car CAN be accelerated from a stop up to 42mph w/ the battery only it is significantly less efficient to do so than to accelerate with the ICE. Remember that all the energy comes from the ICE/gas...all of it, even your regen energy is just the fraction that was recaptured after you used gas to get up to speed. So if you convert that energy via the inverter to store in the battery you have some loss...you have some loss from the storage system (battery) then you have more loss as the energy goes back through the inverter to be used to power MG2 to drive the car...it's far more efficient to power the wheels directly with the energy from the ICE during acceleration when power demands are fairly high.

    When power demands are low the ICE runs in a less efficient rpm range and it becomes more efficient to use the energy stored in the battery that's been saved up from more efficient ICE rpm runs.

    Your car is working normal, just not as you expected.
     
    #3 efusco, Jun 6, 2007
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