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Are you guys extremely light on the pedal?

Discussion in 'Gen 2 Prius Fuel Economy' started by rogerchin, Jul 15, 2024 at 6:57 PM.

  1. rogerchin

    rogerchin New Member

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    I just recently purchased a used 2008 Prius. I noticed my regular driving habit is around 7.5 L/100km, that's about 31mpg. The previous owner got the average to 5.5ish L/100km after driving about 500km.

    Then I discovered that I can coast just using the electric motor by being very light on the peddle, not enabling the engine to do its thing unless necessary. My previous car was a 2011 accord v6, so this fuel economy is a new thing to me and feels super awkward when I'm starting off at a red light like a granny.

    Is this how we're supposed to drive to save gas? When on straight road, use electric motor. When on downhill, foot off the peddle. Only use engine when absolutely necessary, like going up hill.
     
    #1 rogerchin, Jul 15, 2024 at 6:57 PM
  2. Tideland Prius

    Tideland Prius Moderator of the North
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    "Pulse and Glide" is the technique that you want to learn.

    This is where you accelerate moderately (pulse) such that you're using the engine at its efficient rpm to accelerate the car, then once up to speed, you lift off, let the engine shut off then lightly press on the accelerator (glide) such that you're neither using engine power nor battery power (essentially, like being in neutral on a bicycle and not pedalling). This is how you maximise the efficiency of each side of the powertrain.

    If you use the battery, eventually it'll need to be charged either via the engine or going downhill so you want to use as little as possible to stretch the battery charge. And when you use the engine, you want to use it such that it revs to the optimal rpm range to maximise its fuel usage vs. power output. If you accelerate too hard, then you're either using too much fuel (obviously) or the computer may choose a different rpm than optimal and either use the battery to supplement power or over produce power and send the excess into the battery to charge it (which will incur charging losses... gas tank to engine to elec. motor to battery and then elec. motor to wheels. Ideally, you'd want gas tank to engine to wheel or gas tank to engine to elec. motor to wheel).
     
    #2 Tideland Prius, Jul 15, 2024 at 11:03 PM
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