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20% Drop in MPG after 60000 Mi Service

Discussion in 'Gen 2 Prius Fuel Economy' started by msquared48, Dec 15, 2009.

  1. msquared48

    msquared48 New Member

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    Everett, WA, USA
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    2007 Prius
    Just had my 60000 mile service about a month ago and my mileage has dropped significantly from around 52 to 42 now. I do not think that it's all the cold weather and gas additives, but I know that plays a large part.

    Last year in similar weather I was getting 47-48 mpg. I think I'm going to take it back in and see if the adjustments were properly made during that service. I'm suspicious. :confused:

    Any other thoughts or recommendations? I see a lot of people here are experiencing a similar drop as the car ages. I just had fuel efficient tires installed 5000 miles ago too.

    Any changes in the computer programming that would do this, ie, "upgrades"?

    I just reset the average mileage button as it was rapidly dropping and was leveraged with a lot of miles. That's when I saw the latest average reading of 42 after 100 miles. I am going on a longer trip today to see what that does - another 100 miles on the freeway. However, I've always seemed to get better mileage on the freeway than in town.
     
    #1 msquared48, Dec 15, 2009
  2. Codyroo

    Codyroo Senior Member

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    Pleasanton, Ca
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    2010 Prius
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    IV
    Two things to check, right off the bat.

    1) Tire pressure.
    2) Oil fill level.

    Check tire pressures to see if they are "low", where "low" is lower than what you normally run your pressures. If you were running tire pressures close to 40, potentially the dealer returned the pressures to the recommended 35/33, and this would impact your mileage a small amount.

    There have been a number of threads detailing people going to have their car serviced and having lower mpg's afterwards. One item that came up was the oil level being too high (dealer not fully draining the oil out of the car, thus when replacing the oil, the oil level is above the top dot on the dipstick. This has reported to have a much more significant impact on mpg's. Dealers can remove extra oil.

    Lastly, yes weather and winter blends can impact mpgs, as can the heater level setting in the car. But if the mpg drop was steep, check out #1 and #2 first.

    Good luck!
     
    #2 Codyroo, Dec 15, 2009
    2 people like this.
  3. richard schumacher

    richard schumacher shortbus driver

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    #3 richard schumacher, Dec 15, 2009
  4. msquared48

    msquared48 New Member

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    Everett, WA, USA
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    2007 Prius
    Thanks guys. After the run to the airport, the overall for the last 150 is 48+, so maybe things are OK, for now. I'll keep monitoring things though, and I will check the oil level.
     
    #4 msquared48, Dec 15, 2009
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