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re gas pedal technique

Discussion in 'Newbie Forum' started by BrennanShilohRescue, Jan 24, 2009.

  1. BrennanShilohRescue

    BrennanShilohRescue New Member

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    hello all,
    i've been reading posts about how to achieve the best MPG....and i must admit my head is spinning. and i haven't found what i'm looking for:
    re gas pedal use, do we get better gas mileage if we -
    1.) keep a light, steady, even, low pressure on the pedal until we reach our desired speed slowly, or
    2.) give it a harder foot down initially to get to our desired speed quicker, and thereby being able to let up altogether on the pedal sooner, or
    3.) do a tap, tap, tap on the pedal. ie, light, quick little presses, never leaving continuous pressure on the pedal.
    i can't figure it out.
    thanks,
    laura, newbie
    ps: i do love this car :)
     
  2. snead_c

    snead_c Jam Ma's Car

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    :welcome:
    As one Newbie to another (who happens to have a daughter named Laura)hopefully without sounding like I really know how...there are experts on high miles per gallon driving on this site...
    For a beginner like us...
    I accelerate somewhere between your numbers 1 and 2. I call it moderate pressure on the gas.
    I get to my desired speed and (assuming traffic allows) very lightly back off the gas pedal just enough to get the current MPG bar graph to jump up (usually to 100 MPG if the engine is warmed up.)
    I hold that light pressure on the gas without letting the speed drop too low for traffic conditions and then lightly move my speed up and start over again. This is very easy to do on a decent.
    Climbing a hill requires more skill in using momentum going up and slightly coasting as you approach the top and then using light to no pressure going down.
    Please note I'm a beginner and there are PC members who can do this so well they average 60 and even 70+ MPG...but I suspect they started as we do and grew in their skill to control their gas input.
    Another thing to remember is that even when driving liike you used to before Prius days you're going to double your MPG...ENJOY.
    PC Experts, please jump in if you can help us beginners with simple and better directions since I'm still learning and don't want to lead someone astray.
     
  3. kenoarto

    kenoarto Senior Member

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    Suggest you do a search for the term "pulse and glide" on this forum and at cleanmpg.com
     
  4. snead_c

    snead_c Jam Ma's Car

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    Thanks kenoarto.
    Laura these are some of the sites sugested :

    Beating the EPA - The Why’s and How to Hypermile - CleanMPG Forums

    Hypermiling ? Evaluating common fuel-economy tips on the road: Consumer Reports Cars Blog

    Cops: "Hypermiling" Often Risky, Illegal, AAA Agrees; Master Hypermiler Clarifies Suggested Techniques, Tells Motorists To Steer Clear Of Dangerous Maneuvers - CBS News

    Remember to use what you are comfortable with in traffic. :)
     
  5. Prius 07

    Prius 07 Member

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    Hi and Welcome Laura Newbie ;)

    It's been suggested to try to accelerate so that iMPG = ~ 1/2 MPH. Enjoy your new wheels.
     
  6. qbee42

    qbee42 My other car is a boat

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    Without instrumentation, the above rule of thumb is reasonable. Here is what you are dealing with during acceleration: The gasoline engine in the Prius, like all gasoline engines, uses a throttle plate to control engine power. Opening the throttle allows more air to enter the engine, for which more fuel is injected, producing more power. At low power, a gasoline engine is inefficient, due to frictional losses and pumping losses. Pumping losses are large at low speed because the throttle plate is closed or nearly closed. The engine has to suck air through a very small opening. As engine power output increases, the efficiency increases until the engine reaches high RPMs. The exact speed varies, but at high RPMs a lot of parts are moving at very high speeds, and it gets hard to optimally open and close valves, charge the engine, and otherwise operate.

    Given all that, what we are after is running the gas engine at the magic speed which produces the best efficiency, but not pressing so hard on the accelerator that we start draining energy from the battery or forcing the engine to inefficient high RPMs. Most people will tell you to accelerate briskly, which is true but ambiguous.

    Obviously, this brisk acceleration recommendation is only valid when you can stay at speed for some distance. It makes no sense to accelerate briskly only to slam on the brakes for a traffic light. If you are going to drive for a while at a given speed, accelerate briskly up to that speed and stay there. Anticipate stops and slowdowns. Try to avoid driving in electric mode, unless it is for short distances in traffic.

    Lastly, do some more reading on PC. There is lots of good information.

    Tom
     
  7. BrennanShilohRescue

    BrennanShilohRescue New Member

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    thanks to all who wrote back. wow, there definitely is a learning curve.
    laura :)
     
  8. qbee42

    qbee42 My other car is a boat

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    The good news is that you can drive it like a normal car and get great gas mileage. All of this advice is for improving an already great thing.

    Tom
     
  9. BrennanShilohRescue

    BrennanShilohRescue New Member

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    >The good news is that you can drive it like a normal car and get great gas mileage. >All of this advice is for improving an already great thing.
    >Tom

    hi Tom,
    yep, you're so right! i got 48 MPG average in the first week, and i didn't even know about any of this stuff. part of me thinks i should just drive my normal way and forget about it. but another part of me can't help but want to see how much better i can get at it.
    laura :)
     
  10. qbee42

    qbee42 My other car is a boat

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    The Prius does that to people. All of the feedback makes it like a rolling video game. There are a lot of simple tricks, such as avoiding short trips, or combining them into one longer trip. Anticipating stops and allowing enough distance from the car in front are also simple and effective.

    One of the biggest traps for new Prius owners is to be seduced by Electric Vehicle mode, or EV mode. Most new owners think EV mode gives them the best mileage, because the mileage does go up during EV operation. What they fail to realize is that they will pay for that later when the engine has to burn gas to charge the battery, which is less efficient overall than just using the engine in the first place.

    Tom