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Battery Performance at 100K

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by flarend, Mar 1, 2010.

  1. flarend

    flarend Junior Member

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    My 2006 prius is now at 96K and I've noticed a 'considerable' decrease (see below for numbers) in MPG, especially over the past 6-8 months. I've entered data from nearly every fillup from day one (missing 18 fillups out of over 250 which I'll blame on the other person who drives the car). My question is if others have noticed this type of decrease. I'm pondering whether I should take it in for a service call and have my complaint filed before the warranty is over. I've also noticed other things like the batteries not getting to full bars by the time I reach the bottom of a regularly traveled mountain road. Or that the engine seems to be working much harder to go uphill than it used to.

    The seasonal variation in MPG due to weather is quite clear and I'll get much better mileage in the summer compared to winter. The numbers below are from the computer, which is about 1.4 higher than the real mpg for whatever reason.

    avg mpg 5-best mpgs 5-worst mpgs
    year 1 48.2 56.9-61.4 33.8-41.7
    year 2 47.2 53.4-55.1 39.6-41.8
    year 3 45.9 50.7-53.0 33.5-40.5
    year 4 44.4 47.8-49.9 35.9-39.8
     
    #1 flarend, Mar 1, 2010
  2. efusco

    efusco Moderator Emeritus
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    I would suspect that if you're not seeing any significant change in battery behavior (wild swings from 1-2 pink bars to 5-6 purple bars in very short time) that it is something else. I'm at 96k miles on my '04 and am experiencing as good or better MPG than ever.

    Have you replaced your 12v/accessory battery? It can play a roll in MPG. What other factors have you looked at? Have you moved and/or changed your commute in the past year or so? When's the last time you looked at tire pressures?

    I'd also suggest that since you're close to 100k miles that you go ahead and schedule your 100k mile maintenance. Why not have the fuel injectors cleaned, the MAF sensor cleaned, fluids changed, etc. Mention the drop in FE and ask the dealer to look into it in case they can/do find something significant with the hybrid system so they can address it while you're still under the 100k mile warranty.

    But a sub-10% drop in FE really isn't that bad, and many many factors could be at play, I suspect that the HV battery is not one of those factors.
     
    #2 efusco, Mar 1, 2010
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