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I "know" somerthing is wrong with a sensor ?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ddlegg, Aug 24, 2007.

  1. ddlegg

    ddlegg New Member

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    Yesterday I joined PriusChat & regret that I have joined before now after looking @ the Care ,Maintenanance & Troubleshooting section. Yesterday, I posted what I'm going to talk about now in an incorrect section. So I'm trying again
    My Prius has covered 45,356 miles . I've played like a Strad. I've tried to milk it for every precious drop of fuel. I list the TLC I"ve expended :
    A) Oil changes-----Almost always on the 5k miles. Synthetic oil starting @ 10k . Always a new filter w/i
    gasket. Never over-filling a 1/4" showing from the top of the 'full" mark. 5 W 30 oil.

    B) Air Filter ---- checked once a month. I replaced the Toyota filter with a K & N hi flow filter @ 43,350
    miles.

    C) Tires a new ste @ 31,544 miles ( noticeable increase in fuel consumption until the nobs wore off the
    tires. I've run with pressures for the last 40k of 44psi--front & 42 psi ----rear. I check the pressure
    ( cold ) every 7 days.

    D) Front end was realigned after the new tires.

    E) Ventilation Valve replaced @ 43,350 miles

    F) Brakes checked for drag.

    G) Fuel additive toclean the injectors @ 35k miles

    H) Driving habits have improved since first driving the Prius. Even then (at first blush ) I was getting high
    49mpg to low 50 s & on a long trip I got 58.77 ( calculated ) !

    Now to my problem. From Mar 04 ( purchase date ) thru Dec. 04 the monthly average consumption was
    49.93mpg. Jan 05 ... Dec. 05 ave. consumption was 49.45 mpg. Jan 06 ... Dec. 06 ave . consumption was 47.57 mpg.. Jan. 07.... to present 47.20 mpg. The running average to this date is
    48.3 mpg.
    As you can see there has been a steady decline . I think there is something wrong some where .
    Has anyone had a similar problem or am I being too anal ? HELP
     
    #1 ddlegg, Aug 24, 2007
  2. FL_Prius_Driver

    FL_Prius_Driver Senior Member

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    <div class='quotetop'>QUOTE(DD33 @ Aug 24 2007, 08:16 PM) [snapback]501820[/snapback]</div>
    I have a 2001 and over the life of the vehicle there has been about a 7% drop. Having the main battery replaced this year improved the MPG up about 1-4 % (still collecting data). The bigger surprise is changing tires causes a jump in MPG. Sometimes up, sometimes down. Lot of factors to consider here. (Changed tires yet?) Much bigger variation result from weather and air conditioning load (summer MPG is better). Also a factor is the car having more drivers. (Are you the only driver?)

    Nothing appears to be significantly wrong, your data match what I have experienced. This does not rule out something happening, but keep in mind you are talking 5% and most cars MPG drops over their life. It seems that the Prius is under the microscope to a much greater extent.
     
    #2 FL_Prius_Driver, Aug 24, 2007
  3. patsparks

    patsparks An Aussie perspective

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    I'd look at driving style and traffic conditions.
    More gliding less braking, look ahead and plan.
    Remove all the junk from the car, make it light.
    Personally I'd put a genuine air filter back in too, If K&N was the best choice I think Toyota would have used it. Just my opinion though, not tested. I just recall in trade school how the lecturers would rave about how much better paper filters were over foam and oil.
     
    #3 patsparks, Aug 24, 2007
  4. hobbit

    hobbit Senior Member

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    Get a scantool on it and start looking at your fuel trims.
    .
    _H*
     
    #4 hobbit, Aug 25, 2007
  5. ddlegg

    ddlegg New Member

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    Thanks for all the prompt responses.
    Re: K & N filter . I've used K & N filters on 3 cars & trucks with what appeared to be helpful increasing
    MPG by ~ 1.4% ( ave.) So that's why I thought it would be a good idea to try it in the Prius.
     
    #5 ddlegg, Aug 25, 2007
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