Why mileage gets worse in winter

Discussion in 'Gen 3 Prius Fuel Economy' started by cwerdna, Oct 30, 2011.

  1. googrx

    googrx New Member

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    But the Japanese have winter as Americans. It is not just designed for tropic region. This is a myth you must debunk! In fairness, the battery may discharge faster in a colder environment but there is insulation in every Prius and there is a temperature range for it. Check with Toyota!!
     
  2. F8L

    F8L Protecting Habitat & AG Lands

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    What's a myth?
     
  3. rrolff

    rrolff Prius Surgeon

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    There's a lot of talk about blocking grills etc. Here in CA, winter gas is the cause.

    I get a steady 48.5MPG - except during the winter - I'm now getting 43.5 (and we have great weather)...
     
  4. F8L

    F8L Protecting Habitat & AG Lands

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    You mean SoCal. Don't lump us all together with you warm weather water stealing heathens. :p
     
  5. ForestBeekeeper

    ForestBeekeeper Active Member

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    I think he is saying that it is a myth to assume that Japan does not experience -20F winters and therefore design their automobiles to perform well during winter weather.
     
  6. alfon

    alfon Senior Member

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    Just filled up today. The weather was great today with 55 degree temps and no rain, dry roads. Last fillup was 45.5, today it was 51.008 mpg both calculated of course.

    No doubt dry roads and a 10-15 degree increase in temperature did it.

    al
     
  7. RICKKONK

    RICKKONK Junior Member

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    My MPG has droped from a 48-50 range to 43-44 since November when it got colder and wetter. It sucks but I'm sure my 2006 Civic had lower MPG durring the winter months also.
     
  8. SageBrush

    SageBrush Senior Member

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    This sucks. I can barely hit 49 mpg by the fuel meter this tank in my CT, let alone a measly 50. So what if I drove 70 mph going to work with speeds up to 80 ?

    Maybe I'll talk to a lawyer.

    [/sarcasm off] (but true facts)
     
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  9. darelldd

    darelldd Prius is our Gas Guzzler

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    It's a conspiracy!

    The good news is that my EV still gets the same gas mileage it ever did.
     
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  10. darelldd

    darelldd Prius is our Gas Guzzler

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    It's a conspiracy!

    The good news is that my EV still gets the same gas mileage it ever did.
     
  11. F8L

    F8L Protecting Habitat & AG Lands

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    Infinite gas mileage rocks. Or is it zero miles per gallon? :confused:
     
  12. cosgrove

    cosgrove Junior Member

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    One factor I noticed significantly affects gas milage is wind - we live in northern New Mexico where spring winds of 40-50 mph are not uncommon. Driving into a 40 mph wind reduces our Gen III milage by at least 5-6 mpg over a 60 mi trip, but with the same velocity tailwind we gain maybe 3-4 mpg - not sure why, something to do with aerodynamics I guess.
     
  13. litesong

    litesong Active Member

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    When northern fall cooled last year, my mpg began dropping as it normally did, due to temperatures(of course), winter gas, other factors. I experimented for the 2nd time with 100% pure(ethanol-free) gasoline. Unlike my previous attempt, I had years of accurate mpg data on my past use of 10% ethanol blended gasolines in our 3 cars, summarized in the excellent line-graphs automatically generated from the data at fueleconomy.gov.

    Now with 8 months of 100% pure gasoline use, I can easily see that winter mpg stopped dropping in all 3 cars with the beginning use of 100% pure gasoline. As 78bonanza mentioned, winter time starting of my 24 year old Ford Festiva became more difficult. As of this time, mpg increases of all 3 cars have increased by 8%, 7-8%, & 6%. Besides the difficulty of starting my Ford Festiva, once warmed, all 3 cars ran smoother, quieter & with extra power with 100% pure gasoline.
     
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  14. StockBlak11

    StockBlak11 Junior Member

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    @lifesong: I know this is a little late (both in the season and to get back to you), but where in the **** did you find 100% ethanol-free gasoline? I was just driving yesterday between Connecticut and New Hampshire in the typical spring crud we get out here in New England (a lot like Seatlle's ... rain/drizzle, 55-60 F if you're lucky), and I was lucky to break 49.0 at times. I'm pretty sure we must be driving on at least 10% ethanol. Funny how that (sorta) lines up with your pure gas numbers ... you say you see just sub-10% mileage gains with pure petroleum-based fuel. You've really made me wonder.

    I wonder if the less-than-warm air temp plus sky-high relative humidity had something to do with the lower-than-expected (I can usually nail down 53 or so without hypermiling) mileage yesterday. Plus the weird fuel we drive on up here.
     
  15. litesong

    litesong Active Member

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    One of the greatest ways to stop the decrease in mpg in winter is to use 100% pure gasoline. I started using 100% pure gasoline last year as the weather cooled in the autumn. With accurate prior 10% ethanol records, our usual cool weather drop in mpg came to an abrupt halt for all 3 cars. As of late June, our 3 cars' mpg increases are 8.5%, 7-8%, & 5%. Further proof that 100% pure gasoline is best in engines designed for 100% pure gasoline(duh), all engines run smoother, quieter & with more power, such that less downshifting is needed while ascending hills.
     
  16. ForestBeekeeper

    ForestBeekeeper Active Member

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    From about mid-1990s I have not able to find any gasoline without at least 10% ethanol added to it.
     
  17. fuzzy1

    fuzzy1 Senior Member

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    Then why did I still have the regular winter mpg decrease even decades ago, when all fuel was still 100% gas?

    This was before the winter-only ethanol mandate.
    I'm surprised your improvement is that low. Back in the original 100% gas days, my winter-summer difference was above 10%.

    Disclosure time: do you have a financial interest in selling pure gas? While I also dislike ethanol, your handle is splattered all over the web on this one topic.
     
  18. Mendel Leisk

    Mendel Leisk Sand Pounder

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    In Canada Chevron say's their highest octane gas is ethanol free. So far I've not tried it, just can't justify the price and unecessarily high octane.
     
  19. F8L

    F8L Protecting Habitat & AG Lands

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    If you do not stop posting BS about puregas I am going to file a complain with the moderators to get you booted. I'm sure I'm not the only one, on this forum and the other 10 you post this drivel at, who is tired of it.
     
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  20. litesong

    litesong Active Member

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