MFD

Discussion in 'Gen 2 Prius Fuel Economy' started by lexidium, Jul 5, 2019.

  1. lexidium

    lexidium Junior Member

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    I'm always surprised at the mileage people say they are getting.
    Mine's a 2008UK (85,000 Miles) and I always endeavour to drive in the optimum Prius way where possible.
    My MFD over a long period usually shows between 62 and 65 mpg which is considerably higher than some others are quoting.
    What's the general consensus as to the percentage of accuracy of the MFD readings?
    I should also add that it seems a bit better since the new cat and new 12v battery - although whether this has any bearing, I don't know.
     
  2. bisco

    bisco cookie crumbler

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    seems to be around 3-6% optimistic. are you saying that 62-65mpg is lower or higher than what you're reading?
    so much depends on driving conditions.
     
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  3. lexidium

    lexidium Junior Member

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    That's what reads: I reset it usually when I put petrol in but it soon gets to those parameters
    [​IMG]
     
  4. VFerdman

    VFerdman Senior Member

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    What are you measuring at the pump? Also, others may be reporting US gallons in MPG. For example, my average since I bought mine almost two years ago is about 44 and change MPG. That's US gallons. In imperial it would be more because imperial gallon is larger than US gallon.
     
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  5. lexidium

    lexidium Junior Member

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    That's true about US gallons. I'll have to have a look back and see who's saying what.
    I suppose in the end though, that it is what it is - accurate or not - and I can't make it do any more.
     
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  6. Data Daedalus

    Data Daedalus Senior Member

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    IMG_0803.jpg

    Just pulled in to refuel barely two hours ago; managed to stretch it to 601 miles (44 litres went back in). I have 64.0mpg on the MFD.

    It could have been higher, but I got stuck in huge traffic congestion 3 times during my commute home, due to road traffic accidents along my route. The type of congestion that depletes your Traction Battery and forces your engine to kick in and start recharging it. Also had 2 x rainy days which reduce MPG.

    Otherwise, this is normal driving, and crucially, with a non-OEM cat now installed under “The Spaceship” since my original OEM one was stolen while I was attending a funeral.



    iPhone 6s +
     
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  7. VFerdman

    VFerdman Senior Member

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    The difference between US and Imperial gallon is 20%, so you are still showing very impressive fuel economy. I just measure mine at the pump. My Fuelly signature represents actual at the pump number since I bought the car 2 years ago (with 175K miles on the clock). I notice that winter driving really robs a lot of economy, about 10% or more. Summer driving is great, even with AC. My MFD is actually fairly accurate most of the time, but every now and again it is not. My gen 2 with a bladder fuel tank is kind of tricky to know the range, so I tend to fuel up when I have 1 bar on the fuel gauge (which is also not always accurate).
     
  8. NortTexSalv04Prius

    NortTexSalv04Prius Active Member

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    Question:
    What petrol/ gasoline mix(grade/type) that you have used and currently continue to get at the nearby/local petrol pump?

    Here in the USA and more specifically and locally in North Texas (DFW/Dallas)
    There are about two to three grades of gasoline currently locally available
    Regular grade 87 octane 10%percent ethanol mandated currently $2.43 gallon
    Mid grade 88-89 octane grade
    Premium 93 octane $2.57
    E15 88 octane grade
    Pure Unleaded grade

    I currently pump the regular grade into my Gen2 Prius and curious what the specification of your petrol mix?
    Gasoline and Diesel Fuel Update - Energy Information Administration
     
  9. VFerdman

    VFerdman Senior Member

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    I always use "regular", 87 octane E10 that is sold here and in most of US.
     
  10. NortTexSalv04Prius

    NortTexSalv04Prius Active Member

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    More curious about UK /Manchester and OP PC

    You are using the same /similar fuel I get here in North Texas regular 10 percent ethanol …..
    I can drive for about 51 minutes away from home and get ethanol free. I am also averaging about 51 mpg.
     
  11. lexidium

    lexidium Junior Member

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    Just regular or diesel available at my local supermarket petrol station.
    Not sure what it consists of.
    Just catching a plane for Vietnam so not back for 2 weeks or so.