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Strange consumption readings during warm-up

Discussion in 'Gen 3 Prius Main Forum' started by Sergei, Jul 28, 2009.

  1. Sergei

    Sergei New Member

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    Hello,

    Was wondering if someone had observed the following with 2010:

    During warm-up when stopping the instantaneous consumption reading suddenly peaks. It could be mid-range when driving but when slowing down and stopping it would suddenly peak at max for a few sec before going down and what seems like ICE turning off.

    Doesn't happen anymore once warm-up is complete in 4 min or so.

    Any explanation?

    Thanks!
     
  2. Sergei

    Sergei New Member

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    Hello again,

    Was wondering if anyone is observing what I've described...

    Thanks!!!
     
  3. jestoy7

    jestoy7 New Member

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    If you let off the throttle and the guage peaks at 100 mpg, do you see the Hybrid System Indicator shutting off the motor? It could be just a temporary shutoff. I've seen that happen during my commute, but not during warm-up.

    I've observed something different during warm-up. When I first turn on the car in the morning or leaving work, the ICE comes on and for the whole warm-up period (about the same 4 mins you mention) the ICE is on and the mpg meter is pegged at the bottom. This also takes a toll on my "Cons MPG" number.

    Is there a "best practice" for warm-up and optimal driving pattern for FE during warm-up periods?
     
  4. qbee42

    qbee42 My other car is a boat

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    Best practice for warm up is to drive without heavy acceleration. The ICE doesn't develop a lot of power during initial warm up, so heavy acceleration pulls energy from the battery, which must be replaced at a later time and greater cost.

    Tom
     
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  5. jay_man2

    jay_man2 jay_man_also

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    Just drive gently for the first few minutes. In my morning and evening commutes I just take it easy getting out of the neighborhood, and by the time I hit the on-ramp to the interstate it's all warmed up.
     
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  6. jestoy7

    jestoy7 New Member

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    Thanks, do you both also notice that the instant mpg is pegged low even on easy driving?

    For example, I park on the 5th level of a parking garage. When I leave work about 2-3 minutes of warm up are very minimal acceleration and downhill. However, my mpg is pegged at the bottom the whole time.
     
  7. jay_man2

    jay_man2 jay_man_also

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    During warmup it's difficult to get the instant mpg even a third up the scale.
     
  8. qbee42

    qbee42 My other car is a boat

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    Yes, as fuel is being burned to heat the engine and emission control system.

    Tom