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MPG from a dead stop

Discussion in 'Gen 3 Prius Fuel Economy' started by keenanz0316, Sep 2, 2010.

  1. keenanz0316

    keenanz0316 New Member

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    Hello All,
    I have been in and out for the past 2 months or so. I purchased my 2010 Red Prius about 2.5 months ago. This is my first post so go easy on me :)

    From a dead stop to get better MPG, would I use the battery (100% EV Mode) to get up to 25mph or use the normal acceleration via ECO mode? I typically get 58-59mpg in the city, but my best was 62, all non calculated. I have read the calculation is incorrect.

    Any ideas? Has this ever been tested?

    Thank you,

    -Keenan
     
  2. macman408

    macman408 Electron Guidance Counselor

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    As everybody in this forum will always tell you (and I'm surprised they haven't yet), the best fuel economy is achieved by not using the battery at all. Drive like you have no brakes (ie anticipate far in advance). The battery is useful only for recapturing energy that you unavoidably wasted. The only time using EV is better is if you are approaching a long, steep hill where the battery would otherwise fill all the way - by emptying the battery before going down the hill, you can capture more energy on the way down. However, this is very rare for most people - you'll know you should have discharged the battery a bit if you hear engine braking start on the hill, which happens a short time after the top bar on the battery is illuminated.

    Using EV is also good if you need to move the car over a few parking spaces, since it avoids an engine warm-up cycle, which is inefficient. However, the car has many conditions that can prevent you from going into EV immediately after turning it on (for starters, you have to do it within 10 seconds, and the engine can't be too cold, and the battery can't be too hot).
     
  3. qbee42

    qbee42 My other car is a boat

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    Sound advice above. Accelerate briskly, but not so hard that the car starts to use the battery.

    There are exceptions, of course. If the road ahead is not clear, it makes no sense to accelerate briskly and then brake to slow down. Likewise it makes no sense in stop and go traffic. In stop and go traffic the battery and EV will be more efficient than the gas engine. The gas engine will come on from time to time as needed to charge the battery.

    Mostly just drive your Prius and don't worry about it. Start briskly, try to time lights to avoid stopping, and keep your speed at a moderate level. Do all of those and you will get great mileage.

    Tom
     
  4. xs650

    xs650 Senior Member

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    It's also good for seriously slow stop and go traffic.
     
  5. keenanz0316

    keenanz0316 New Member

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    Thanks all, any other tips?
     
  6. ksstathead

    ksstathead Active Member

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    Keep those tires firm. psi=mpg.
     
  7. Michaelvickdog123

    Michaelvickdog123 New Member

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    Might also add, and based on my driving experiences...I get just as good MPGs in the "PWR" mode as I did in the "ECO" mode. For the past few weeks, I've been averaging just over 61 MPGs in my commute - that represents an average over about 700 miles in PWR mode. I prefer the PWR mode as it's quicker response from a stop.

    Getting good MPGs is all about conservation of momentum, ie, as much as possible, minimize the changes in velocity.