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Curious drop in mpg

Discussion in 'Gen 2 Prius Fuel Economy' started by pt95148, Apr 21, 2008.

  1. pt95148

    pt95148 New Member

    Joined:
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    Vehicle:
    2008 Prius


    The best mpg I achieved so far was 49.5mpg on the third tank, I filled up twice since and the mpg has been dropping steadily to 48.1mpg.

    The car has just 1500 miles on it of mostly city driving, I have not changed my driving style of normal acceleration, hit cc as soon as I got to the limit, release cc and coast to red light, stop start traffic, etc
    I pumped at the same station on my commute route.

    If I remember correctly, I pumped the tire pressure to 42/40 on the third tank, and maintained it so far.

    Curious as to what contributed to this drop?

    Thanks
     
  2. Ari

    Ari New Member

    Joined:
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    Location:
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    Vehicle:
    2006 Prius
    I wouldn't worry about it, your car is still brand new and you're a brand new Prius driver. Things will improve!

    Possible causes:
    - Wind
    - Air temperature
    - Any small errands you ran
    - Gas quality (even though you used the same station...)
    - Traffic patterns
    - Increased cabin heater use

    What you can do next:
    - Wean yourself from the CC
    - Buy a Scangauge and keep your RPMs below 2400 at all times.
    - Pump your tires to 44/42
    - Turn on the heater only after the engine has warmed up from driving.

    Even at 48 you're already doing great and it's the average Prius MPG according to greenhybrid.com.
     
  3. Prius 07

    Prius 07 Member

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    2007 Prius
    That's a very small variation and you're getting pretty good mileage for pre-break in (car and driver:)).
     
  4. JimN

    JimN Let the games begin!

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    Vehicle:
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    Welcome. Neighbor? Sounds like you are off to a good start. You will probably do better if you can maintain a steadier speed. Try accelerating to limit minus 5 and hold until you start coasting to the next traffic light.

    For example, the speed limit on US130 is 50mph but it doesn't make sense to accelerate to 50 just so I can brake to a stop at the next traffic light. I accelerate up to 40 or 45, and coast into the light. When timed right I don't even have to apply the brake. You'll be passed along the way but then pull up to them at the light. Driving a bit slower and at a more constant speed is pushing the tank's mpg according to the MFD up through the 50's.

    I would also suggest keeping the upper grill blocked all year.

    Rounding off the gas purchase or pumping an extra tenth of a gallon has a dramatic effect on that tank's economy. For example:

    300 miles, 6.0 gallons is 50mpg
    300 miles, 6.1 gallons is 49.18mpg (< 30c more)
     
  5. Genoz World

    Genoz World ZEN-style living

    Joined:
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    heeeeyyyyyy.......

    dont sweat it! just drive, your car is brand new, you're a new HYPERMILER, yadda yadda..............

    just enjoy things and drive as efficiently as you can. learn from the people here about hypermiling, dont drive it like a gas car and you'll do great.

    i started off at 45-46, now, when i mix mature driving and "smart-driving", i have noticed the likes of 52mpg. and NOOOOOOOO, it's NOT like granny driving.

    mine has 3200 miles now......can't wait til 5000.

    good luck
     
  6. pt95148

    pt95148 New Member

    Joined:
    Dec 28, 2007
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    Location:
    SJ
    Vehicle:
    2008 Prius
    Thanks everybody for your feedback.

    I am not complaining or worried, just curious about the steady drop.