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Gas Mileage Went Down 11 MPG

Discussion in 'Gen 4 Prius Fuel Economy' started by Coast Cruiser, Dec 2, 2016.

  1. Coast Cruiser

    Coast Cruiser Senior Member

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    I went from a steady and consistent 62 mpg calculated, down to 51-52 mpg. Not complaining, just making an observation. I'm still very satisfied with anything over 40. :LOL:

    I haven't changed the way I drive. Has to be due to the weather change? Finally have some cooler temps in Southern California. 46 degrees in the early morning, to mid 60's in afternoon. I don't consider that to be "cold" by any means... People on the East Coast are laughing at us. Buy it sure affected my gas mileage. Most of my driving is in the early hours. I noticed the gas engine stays on a longer in the morning.

    I wonder what mpg you guys get in the freezing snowy states?
     
  2. Prodigyplace

    Prodigyplace Senior Member

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    I know our fuel blend changes for winter hurting mileage too. With our hills I usually get more than that. Must be too much fast food. Filling stations are for the car, not you. :D
     
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  3. Prodigyplace

    Prodigyplace Senior Member

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    I first read the title as mileage went down to 11 MPG and I thought you really decided to take advantage of your beloved Power mode. :LOL:

    I actually showed just over 11 MPG at the end of our 0.4 mile street. I had let the engine run a few seconds to try & get the frost off the windshield, though. Home said temperature was 31. Prius said 36.
     
    #3 Prodigyplace, Dec 2, 2016
    Last edited: Dec 2, 2016
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  4. bisco

    bisco cookie crumbler

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    is that measured by the tank?
     
  5. Dragon Rider

    Dragon Rider Active Member

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    The weather here was around 75 degree it went down from 71 mpg to 62 mpg. Normal here is around 95 degree . The weather has a lot to do with how the Prius function.

    Posted via the PriusChat mobile app.
     
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  6. iplug

    iplug Senior Member

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    Some possible factors for mpg decrease this time of year:

    -extra cold start mpg penalty during winter, most severely effecting trips of only a few miles (due to longer time for engine to reach optimal operating temperature)
    -loss of tire pressure in winter (increased rolling resistance)
    -use of heater/heated seats/window defrosters during winter
    -more air drag from colder/denser air (for highway driving)
    -winter grade gasoline (less energy dense than summer blend)
    -decreased battery performance when cold
    -if present, ice/snow (and rain which California gets most of in the winter)
     
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  7. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    It's that time of year.....

    1. Set clocks back.
    2. Drive home in the dark.
    3. Put spare change in the kettle in front of stores
    4. Listen to Prius drivers complain about mileage. :)

    I'm into the 40's in the morning, and it cost me a few miles per gallon, but Priuses are still pretty fuel efficient.
    Like........VERY fuel efficient.

    My truck never loses any inefficiency during the winter. I still get 20-21 MPG. :D
     
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  8. first_superior_prius

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    And don't forget wind... in many areas of the country, there are increased winds in late fall and early winter.

    For OP, is it possible he lives in an area that gets Santa Ana winds?

    I drove into a 20MPH headwind the other day, and my mileage dropped by 7 or 8 MPG compared to the previous 2 days, which had light winds and similar temps.
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    The 4th gen is reportedly much more willing to run electric-only. Even on cold starts? Maybe the car's computer has a minimum ambient temp requirement for that? And once temps drop it reverts to more 3rd gen behaviour?

    I find it concerning that Toyota has chosen to use the pack so much more, hope it doesn't backfire. I'd rather have low 50's for mpg, and a more pampered pack.
     
  10. Prodigyplace

    Prodigyplace Senior Member

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    My measurement was from startup, so about 0.4 miles
     
  11. Coast Cruiser

    Coast Cruiser Senior Member

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    I still consider the (full-tank to empty) gas mileage to be excellent at 51 MPG. I'm not disappointed at all, just making an observation, and learning about how my first Prius performs in cooler temps.

    I never check the mpg on daily trips, or short-mileage drives. I usually fill up when the gas gauge reaches the last bar. Sometimes sooner. I deliberately drove a little longer this time, and let the tank empty more so that I could learn how the car performs in these "California winter" temperatures of 60. :LOL: (I wonder how a Prius would perform in Montana, where my sister is expecting a high of 10°, and a low of -2!)

    Oddly, and strangely I still get the best gas mileage when I'm in the PWR mode. I no longer try and figure it out, I just enjoy the ride. :)
     
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  12. Dragon Rider

    Dragon Rider Active Member

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    Yes you are right. Well in Power Mode we tend to glide longer than Eco Mode or Normal . I did it this morning in Power Mode. 1480703344869.jpg

    Posted via the PriusChat mobile app.
     
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  13. Prodigyplace

    Prodigyplace Senior Member

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    I might give it a try once I stop improving in Eco mode. My average per day this week appears to be slightly over 58. I think last week was 51.
    Car just turned over 3000 miles.
     
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  14. Dragon Rider

    Dragon Rider Active Member

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    It like Bisco said same thing we do in Eco Mode do in Power Mode. Here in Miami is always 95 degree so that help. My speed was between 60 and 65 mpg.

    Posted via the PriusChat mobile app.
     
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  15. bisco

    bisco cookie crumbler

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    sorry that was for the o/p, but your making my point. you can't judge mpg's by trying to watch the dash.
     
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  16. Coast Cruiser

    Coast Cruiser Senior Member

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    When I turn the car off, the little message says, "Good Eco Driving!" And that's after I've been driving around in the PWR mode all day. :D I can't figure it out, but I always get worse gas mileage in the Eco mode.

    Reply to Mendel: The gas engine starts up immediately in the morning. I don't have the heater on. Or the defroster. And "auto" is not on. I don't see any EV until I've driven about 5 miles... That's in temps of 46 to 55 degrees or so.
     
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  17. Prodigyplace

    Prodigyplace Senior Member

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    I know that, I was just making fun of @Coast Cruiser since he has been boasting of a constant 62 mpg.
     
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  18. first_superior_prius

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    Your speed was between 60 and 65 for the picture (post #12) above? If I am reading right, it took 1 hr, 12 mins to go 35 miles, which is about 30 mph?
     
  19. Dragon Rider

    Dragon Rider Active Member

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    My speed was always between 60 and 65 mpg the whole time . I was in the freeway . The first 10 miles of this trip the speed limit is 45 mpg . I do 90 to 100 miles per days. I am going to work. Pretty much is always the same. How you come up with 30 mph as the average.

    Posted via the PriusChat mobile app.
     
    #19 Dragon Rider, Dec 2, 2016
    Last edited: Dec 2, 2016
  20. Prodigyplace

    Prodigyplace Senior Member

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    You do 90 to 100 mpg per day???