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best acceleration technique

Discussion in 'Gen 2 Prius Fuel Economy' started by kdk84, Apr 30, 2007.

  1. kdk84

    kdk84 New Member

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    I was wondering, since either way it seems like MPG is compromised during acceleration, is it best to accelerate at a moderate speed with slightly higher mpg, or is it better to accelerate harder and to reduce your "getting up to speed" time.

    Perhaps different scenarios (i.e. uphill vs. downhill starts) promote different acceleration techniques for optimal mpg. I was just wonder what your guys' experience has been. I just got my prius last weekend so I'm still new to all of this.
     
  2. JimboK

    JimboK One owner, low mileage

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    <div class='quotetop'>QUOTE(kdk84 @ Apr 30 2007, 02:45 AM) [snapback]432422[/snapback]</div>
    Moderate acceleration is probably better, though it depends on how "moderate" is defined. Some have described a dropoff in ICE efficiency at around 2300-2400 RPM, and then another at around 3000. Of course not having a tachometer, you won't know when you've reached those numbers. (Many of us have aftermarket instrumentation like a ScanGauge.)

    To help guide folks without a tach, lately I've been watching the correlation between RPM, speed, and instantaneous fuel consumption. It appears that if you keep MPG at half the vehicle speed or better, you're probably below 2400 at most speeds. (On this observation, I'm interested in the feedback of others with RPM-monitoring capability, but I am going to start a new thread.)
     
  3. Rangerdavid

    Rangerdavid Senior Member

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    My experience is that the Prius requires a firm, rather quick acceleration. Not to be confused with "floor it!", but a firm foot on the pedal, it will get up to speed quickly. Then I can begin to P&G for mileage. I have tried both techniques, the slow, easy on the pedal acceleration, and the moderate, firm foot on the gas. The Later works better IMHO> :lol:
     
  4. KV55

    KV55 Member

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    Always a good question. Real hard acceleration is certainly not good for fuel economy as it draws from the battery so the ICE wants to charge it up later. There seems that there are two points under acceleration when the car "deadbands", that is there are neither green nor orange arrows to or from the battery on the energy display.

    The lower rpm point is more definite (on the screen) and the higher rpm point is more of a toggle back and forth between the green and orange arrows. Both take some skill in hitting. I can't split the difference in terms of mpg over a journey so maybe the higher rpm and faster acceleration is the best option when everything else is considered. Most likely it will be the speed you stop at that will make the biggest difference.