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Fuel mileage in the toilet now that winter is here

Discussion in 'Gen 3 Prius Fuel Economy' started by K9CRT, Nov 28, 2013.

  1. Mark C.

    Mark C. New Member

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    I live in Alabama and the weather has been cold and rainy here lately and I drive on terrain that includes hills that are high enough that the power indicator goes all the way to max climbing them. I made a lower grill block out of 1/2" pipe insulation by just squeezing them into place. Next, I do not use the "Auto" position for the climate control. The car is garaged over night and I drive about 2 miles before I turn the fan to the lowest setting and another couple before I bump up the fan speed. My commute is almost exactly 20 miles 1 way.

    The result is the car does not fast idle nearly as long just to make the interior warmer sooner and will turn the engine off sooner when coasting. {I use Eco mode > 95% of the time.} Very short trips on very cold day will kill your tank average, but let's try and remember the goal is to use the least amount of gas, not to have the highest displayed fuel economy figure.
     
    hybridbear likes this.
  2. zhenya

    zhenya Active Member

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    Near zero F last night and this morning here, and a couple of my short (3 miles or less) trips have returned 22mpg even in my PiP!
     
  3. markabele

    markabele owner of PiP, then Leaf, then Model 3

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    I hear ya man, it sucks. I had a drive last night where I couldn't even use all my range because the engine was running so much.
     
  4. VicVinegar

    VicVinegar Member

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    I'm down about 5 mpg compared to summer on my commute. I blast heat for a lot of the trip. Still pretty good fuel economy compared to everything else.
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    When at stops you can get the engine to turn on/off by just ticking the cabin temperature setting up/down. The threshold's around 21C, I think depending on coolant temp to some extent.

    Try it: very easy way to improve mileage, just tick the cabin temperature down a degree or two, and engine will shut down. Leave it higher and engine continues to run, assuming cabin comfort trumps economy.
     
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  6. fuzzy1

    fuzzy1 Senior Member

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    My experience is that this is very strongly tied to engine coolant temperature, and happens only in a certain temperature band during warmup. And the band is different in ECO than Normal.

    On my normal route, I usually reach the first stoplight before the temperature climbs to the beginning of this band (103F for my particular settings) but it usually gets there while waiting for the green. A few miles down the road, the temperature climbs high enough that the engine can shut down regardless of climate control setting.
     
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  7. retired4999

    retired4999 Prius driver since 2005

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    Same here, but went about 11 miles 58 mpg! :) Had about 2.8 miles of EV left. My starting EV is down to 9.8 now. :confused:
     
  8. PriusGuy32

    PriusGuy32 Prius Driver Extraordinaire

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    Ugh my mileage went down tons this week - here in Michigan its been in single digits :coffee: And will be a high in the negative digits next week with a wind chill of -30f!!

    Dont even try and talk to me about a 1 or 2 mpg drop....lol Im down to 42mpg, from last weeks 46mpg. :cry:

    My grill is 100% blocked, top and bottom and has been for weeks, I have LRR winter tires on 42f/40r, and I have an engine block heater that runs for 3-4 hours before I leave every morning. I feel like Im losing the battle, as I have no more techniques left in my arsenal.
     
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  9. retired4999

    retired4999 Prius driver since 2005

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    You are doing really well! Keep up the good work.
    Just be glad you're not driving something else because it would be doing worse in those conditions!
    75 day's or so till spring! :D
     
    hybridbear likes this.
  10. csp1971

    csp1971 Junior Member

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    I've been rather surprised how well my Prius does with mpg even with the winter weather ups and downs going from 50's to below 0 windchills. I am on my 4th tank since installing some new winter tires and new wheels and am averaging about 49 mpg. With my old 2000 Civic, I was getting about 29 mpg in the winter and 32 during warmer months.

    I did the lower grill block and have kept the cabin temp at 71 using non-auto setting after the car has warmed up a few minutes.
     
  11. Beelzel

    Beelzel Junior Member

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    While not quite a cure... more like a bandaid. Punch the recirculate button when you use your heater in the winter... like you use to recycle already conditioned/cooled air during AC season. This will make less of a demand on the already heated water in the "thermos"... vice having to bring the bitter cold air up to "livable" temperatures you will just have to being the interior air back up to pleasant. Make sense?
    No, it will not nudge you back up to the 50's in MPG... but, might keep you out of the 30's during the winter.
    N.B. And yes, I understand the fogging potential... just adjust.
     
  12. DavidA

    DavidA Prius owner since July 2009

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    28.5mpg ave. right now, with 100 miles left in the tank. Lowest I've ever seen in this car.
     
  13. markabele

    markabele owner of PiP, then Leaf, then Model 3

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    Wow, what is your average during the summer? And what have temps been like for most of this tank?
     
  14. DavidA

    DavidA Prius owner since July 2009

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    mid to upper 40's. I work one mile from home, hence the big mpg hit. On vacations, I frequently have 51-55mpg tanks. Note: I haven't updated my stats in my sig for about a year now.

    It is now -18F. The past 5 weeks have been way far beyond unseasonably horribly and horrendously cold/snowy/windy/bad (did I use enough superlatives?). When you warm up a car to defrost it for 20 minutes in these temps and then drive a mile, and do that repeatedly, yeah, that does in the mpg's for sure. I don't mind, because the car is very reliable in all other areas and seasons. But right now, I have a flat tire(s) and have to be inside a warm house for an extra day instead of going in to work today to unload trucks outside at the high of -13F.
     
  15. john1701a

    john1701a Prius Guru

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    20 minutes! The longest I've ever let it idle, here in Minnesota, was 4. Warm up is much faster when the engine is being used.
     
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  16. DavidA

    DavidA Prius owner since July 2009

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    I often get ice and frozen fog built up on the inside of the windows as the temps change a lot. Since its concave, it is difficult to scrape that off. Even if I move off in short order, a 5-minute warm up and then a 4.5 minute drive in sub freezing is hell on the mileage.
     
  17. randommonks

    randommonks Member

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    I had a laugh at my mileage this morning. I drove about half a mile on a cold engine. It showed 28F on the car's outside temp gauge and I got 6.8 mpg for the trip. Tanked my average mpg for the mostly full fuel tank from 53ish to 44. :LOL:
     
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  18. hybridbear

    hybridbear Member

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    Yesterday the outside temp was about -15F when my wife drove home from work. Normally she can get 43-45 MPG on that trip in the winter, yesterday it was 35 MPG. We're sick of this stupid Polar Vortex... Grrrrr :mad:
     
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  19. DavidA

    DavidA Prius owner since July 2009

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    Finally up to zero degrees today here! Yea!

    Schwarzenegger as Ben Richards from the movie Running Man...
     
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  20. szgabor

    szgabor Active Member

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    In these last couple of frigid days my mpg dropped about 10 mpg ... on the same route same driving etc. This is with full grill blocking !!! and I only keep heat on when absolutely neccessary

    I fueled up on Thursday just before the snow storm and drove only in the cold days (not Sunday) brrrrrrr.

    Even with some heat on 68F the windows are freezed up !!!!