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Just drove from Michigan to Florda and Back, Huge MPG Difference

Discussion in 'Gen 2 Prius Fuel Economy' started by Justin Case, Dec 31, 2012.

  1. Justin Case

    Justin Case Junior Member

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    Just drove 3,500 miles in 8 days. Started in West Michigan, went as far as the Everglades. I'm driving a 2007 with 145,ooo miles.

    Before we left I was a little worried as mileage dropped to roughly 39-40-mpg in the month prior. I keep up on maintenance, the 12v is original and a little low using the MFD headlight trick, but checks OK at the dealer. Over inflate tires slightly (40psi.

    Anyway we leave and the mileage is 39-40 mpg fully loaded with 4 people in it, even the compartment under that mat in the hatch was loaded. We get into Georgia and it goes up a bit - 42MPG. Get into southern Florida and bingo, getting 44-45 MPG. And once we start driving in that Florida traffic off the highway we get 65 MPG (stop and go).

    Pretty cool to see that change as we drove south into warmer weather. Winter kills he MPG at least 10% for me.
     
    PriusGuy32, uart and usnavystgc like this.
  2. Blu-ray

    Blu-ray Blizzard Brigade #215

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    Yes. I believe you are correct about the temperatures. I live here in Central West Florida. I haven't driven my car much since I bought it mid December, but I have noticed that on the days when it was cold I got considerably less MPG than on the milder days. I wonder what it will be like come the humid icky summer comes which starts here in about a month or two and lasts until November. LOL

    If you've never lived in the southern part of Florida you will know we have

    SUMMER and winter. We bascially have 1.5 seasons here. LOL
     
  3. uart

    uart Senior Member

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    Wow that's a big difference there JC.

    I'd say there must have been a few different things going on there to get such a large change. My guesses are:

    1. Warmer temperatures.
    2. Lower "off highway" speeds (this makes a big difference for me).
    3. Possibly a different gasoline formulation. Does anyone know if there's less (or no) ethanol used in FL.
     
  4. Blu-ray

    Blu-ray Blizzard Brigade #215

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    1. Yes warmer temperatures help because the engine takes less time to warm up. Plus the engine isn't always battling trying to stay warm since it's warmer here.
    2. Yeah, the off highway does make a big difference.
    3. No. We have 10% here just like elsewhere. I only know of two gas stations in my area which offer 100% petrol without ethanol. They both are out in the farming communities.
     
  5. F8L

    F8L Protecting Habitat & AG Lands

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    Umm I'm the REAL Justin Case. Pfft!

    LOL

    I agree. It is amazing what warmer temps do for fuel economy. I hate the winter months.
     
  6. Justin Case

    Justin Case Junior Member

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    I was chatting with the service rep at the dealer when I got home for an oil change. I mentioned the huge MPG difference. He said it also could have been the summer blend used down there since we have a winter blend so the gas "doesn't freeze". Yeah he said that.
     
  7. JimN

    JimN Let the games begin!

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    Yup, when you have to worry about gasoline freezing it's pretty dam cold.
     
  8. techntrek

    techntrek Member

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    Bottom line, cold air is dense air, which means more air to push out of the way during the winter months and so worse MPG.

    This is universal knowledge among pilots. You get a much higher amount of lift in the cold months because of the dense air (and much less lift in the warm months, forcing a lower maximum load if necessary).
     
    friz likes this.