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One year old now and mileage is down

Discussion in 'Gen 3 Prius Fuel Economy' started by Slovewell, Aug 11, 2010.

  1. Slovewell

    Slovewell New Member

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    I have had my 2010 a year and 24,000 miles. I have noticed I am down about 2 MPG. I keep the tires up around 37 PSI like I always have. I don't know if the batteries don't hold a charge as long or it's the engine. I drive the same place and back for work so I am consistent that way. I take the car to Toyota for the oil changes and they rotate my tires so I'm not sure what I can attribute the drop to. I still like the car but I was curious if any one else has seen the same results. The car still looks new except for the leather seats. They are wearing no matter what I do. When I fill up I calculate the mileage and also note the computer's calculations. Right now, I see about 49mpg calculated and 53mpg from the computer. It is all around type of driving, some highway and then some traffic lights. Maybe, the traffic has increased slowly and I didn't notice it.
     
  2. TheSpoils

    TheSpoils Member

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    I also have mine about a year. No change in MPG still between 50-60. Increasing traffic should not impact your mileage, the hybrid is at home in traffic more than on highway. Must be something else.
     
  3. Bica2go

    Bica2go New Member

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    My only ideas of what could be happening are based on what I've learned from here over the past year:

    1. Did you have an oil change recently and check to see if maybe they overfilled it? That seems to happen often.
    2. Are you running the AC more lately? It was hot here in MA in July and I took the trade of running the AC to be comfortable and saw the hit to mpg.
    3. Does VA switch to E10 in the summer? That will drecrease your mpg a bit. I just realized the station I'm using went to E10, sigh.
    4. What tread life is left on your tires? I haven't seen reports of how long the OEM tires last and don't know the impact of the wear. I'm just wondering how they're doing and if it could make a difference.

    Hopefully one of our resident experts will have some other ideas too.
     
  4. Michaelvickdog123

    Michaelvickdog123 New Member

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    There are two times in the year that most of us experience some dip in MPGs - Winter and Summer.

    (1) Winter months because the ICE runs more often to heat the cabin and stabalize the temperature of the cataytic converter.
    Every car that I've ever owned had worse milage in the Winter.

    (2) Summer months most metro regions that have any kind of smog switch to an ethonol-gas mix. Depending on which report you read, that can drop MPGS between 2%-5%. I've even seen it as has as 25% on some trucks.

    http://www.fivecentnickel.com/2006/06/01/ethanol-blended-gas-lower-mileage/
     
  5. andyprius

    andyprius Senior Member

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    Try rebooting
     
  6. turtle0747

    turtle0747 New Member

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    What is a Reboot?
     
  7. eglmainz

    eglmainz New Member

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    I hate to disagree with you here, but I do. In my case, with just over 38,000 miles on my 2010 Prius V, I have not seen any difference in the mileage, thought for an unknown reason earlier in the year (March) I suddently dropped by 2-3 for about 60 days, and never knew why (Oil Overfill?>)

    That said, when I am in heaviest traffic, like stuck in rush hour, my mileage certainly goes down, by at least5-8 mpg, at least for the time that I am stuck idling in traffic, with the A/C on to overcome the 90+ weather and 90% humidity that we have in Chicago. So while I agree the car does great in traffic, and you are still likely among those with the best mileage in that traffic jam, you are still taking a small hit on the mileage, albeit temporarily.
     
  8. Judgeless

    Judgeless Senior Member

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    My Prius is about 13 months old. It has 34,000 miles. Zero repairs. I get an average of 61MPG. I keep my tires at 47/49 PSI. Here are my last 5 tanks for gas. I fill up with about 10 gallon so the math is simple.

    [​IMG]

    I use the A trip for tanks for gas and the B or short trips.
     
  9. Judgeless

    Judgeless Senior Member

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    This is my current tank of gas. 98.7 miles going an average of 46MPG with an average of 61.4 MPG.

    [​IMG]

    I do not drive like an old lady or below the speed limit. 99% of my miles are highway. For me, the car gets horrible MPG’s in the city. I never understood why the car is rated at 51 city 49 highway.
     
  10. dmvp

    dmvp Member

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    I SO agree with you Judgeless!!

    Most of my trips are very short, city/town trips. It's only 2 miles to the grocery store, which I travel to about 3 times a week. My average is around 50 mpg, with an average speed of 30 mph.

    If I decide to take a trip downtown (Chicago), which is about 60 miles away and I take the interstate...I'll average around 65mpg, driving 70-75 mph.

    My car is also over a year old, but I only have about 12.5k miles on it. I haven't noticed any significant change in my mileage.

     
    1 person likes this.
  11. Lottamoxie

    Lottamoxie Member

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    How accurate is the Prius computer/mpg? I thought I read that they can be a few mpg off.
     
  12. eglmainz

    eglmainz New Member

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    Personally, I do not have much faith in it. I've been tracking my mileage since the day I bought her, and use an iPhone app called 'Gas Cubby', and since it has tracked every mile and gallon of fuel, I trust it more than my car's display.

    While I use the displayed mileage as a general guide, I have seen tanks vary 4 mpg in either direction of the actual mileage/fuel math would indicate.
     
  13. Judgeless

    Judgeless Senior Member

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    These numbers should be dead on.

    [​IMG]

    The last tank I drove 637 miles and used 10 gallons of gas. That comes to 63.7 MPG
     
  14. EmuMessenger

    EmuMessenger New Member

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    How are you guys doing this?

    I am 2500 miles into my Prius and my best tank (on the computer) was 48.5. I am never even close to 50MPG, let alone 60 or 80.
     
  15. Judgeless

    Judgeless Senior Member

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    That 87.7 MPG number does not mean anything. It is the best MPG before you reset the trip to zero. I was playing around when I first bought the car and that number is stuck there forever.

    Your car is still new. With time it will get better. I keep my tires over inflated, drive the speed limit and try hard to predict stops. If you see a light just turned yellow and you are 4,000 ft from the light stop giving it gas.
     
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  16. cwerdna

    cwerdna Senior Member

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  17. andyprius

    andyprius Senior Member

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    Disconnecting the neg. ground wire from the chassis to the neg post on the battery. It is also termed resetting, recycling and can also be confused with rurning the power switch off and on. I have posted a thtead on the subject. Do a search on andyprius.:D
     
  18. andyprius

    andyprius Senior Member

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    If you happen to be observing the speed limits your mpg should be way above 50mpg on the 2010. Unless all your trips are uphill, you may have a serious fault. Try rebooting. Search andyprius.
     
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  19. macman408

    macman408 Electron Guidance Counselor

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    I disagree. Especially since EmuMessenger has the Prius V, which has a slight disadvantage for fuel economy due to the 17" rims, even though the EPA rating is identical. 48.5 is in line with what many others are getting, given differences in driving style, ethanol content, weather, terrain, tire pressure, trip distance, highway vs. city, stoplight frequency, etc. etc. etc.

    EmuMessenger; avoid short trips - the Prius typically takes ~5 miles to fully warm up, in my experience. Especially for the first mile or so, your fuel economy will be pretty bad. Accelerate briskly, but avoid filling any significant amount of the PWR bar on the HSI, if you can. Look as far ahead as possible for changing traffic conditions, stop signs, stoplights, or anything else that will make you slow down, and immediately get off the accelerator (or even better, hold it down just enough to glide - nothing in either the CHG or the hybrid area of the HSI). Brake somewhat lightly, avoiding filling the CHG bar completely. And read the many, many threads with more tips like these!
     
  20. bac

    bac Active Member

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    2 mpg is not material.

    -Brad