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Rain = less MPG's

Discussion in 'Gen 3 Prius Fuel Economy' started by alfon, Mar 8, 2010.

  1. alfon

    alfon Senior Member

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    So, yesterday, March 07, 2010 we took a trip from Seaside Oregon to Longview WA. I reset "A" trip to zero and our car was already warmed up from driving a few miles for lunch at Cannon Beach, OR.

    The weather was clear, 54 degrees, roads dry and little wind. "Nice Weather".

    We arrived in Longview with an indicated 62 MPG. Filled up, my wife shopped around and we left.

    The temp had now dropped to bout 45 - 48 degrees and it was now raining and the roadway was wet. Obviously a cold front had moved in , which is often the case in the Northwest.

    We arrived at Seaside with a indicated trip MPG of 50 MPG.

    The differece, rain and wet roads with standing water at times. Temp in the mid 40's.

    I have been driving since 1966 and I have never seen a fluctuation like this.

    Remember the elevation factor is 0 for Saside Oregon, obviously sea level, and Longview, about 50 miles or so up the Columbia River, has to be above sea level. So the trip back was above sea level to sea level as well.

    alfon
     
    #1 alfon, Mar 8, 2010
  2. qbee42

    qbee42 My other car is a boat

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    Rain and cold will do that. The car has to push all that water aside, and colder weather extracts heat from the system.

    All cars suffer from this; most get such poor mileage that you never notice the difference. It's like a 400 pound man gaining 40 pounds; who can tell?

    Tom
     
    #2 qbee42, Mar 8, 2010
  3. ItsNotAboutTheMoney

    ItsNotAboutTheMoney EditProfOptInfoCustomUser Title

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    60 mpg to 50mpg = increase of 1/300 gallons per mile (gpm).

    Corolla AT highway: 34 mpg - 1/300 gpm * = 30.54mpg

    Rav4 highway: 28 mpg - 1/300 gpm * = 25.61mpg

    Tacoma highway: 25 mpg - 1/300 gpm * = 23.08mpg

    Tundra highway: 20 mpg - 1/300 gpm * = 18.75mpg

    While the Prius is affected by adverse conditions more than other vehicles, thinking in miles per gallon is misleading since the drop depends on the original value. What matters is the amount of additional fuel it has to use.

    * Yes, the units are different. By subtracting from economy I mean an increase in fuel consumption.
     
    #3 ItsNotAboutTheMoney, Mar 8, 2010
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  4. spiderman

    spiderman wretched

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    Alfon,
    You might follow IndyKing's example and sell that rotten Prius for another TDI something or another. I think you will be more happy in the long run.
     
    #4 spiderman, Mar 8, 2010
  5. alfon

    alfon Senior Member

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    My wife's car, and she loves it....

    Well I have a 2003 Jetta TDI manual 5-speed, Wagon, and I have never expierenced a drop of 12 MPG due to rain. This car averages 53 MPG, and in winter, rainny weather still 50 MPG or so, not 41 MPG.

    There is something about the Prius and Hybrid cars in general that are quite tempermental in MPG's.

    Alfon
     
    #5 alfon, Mar 8, 2010
  6. spiderman

    spiderman wretched

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    Yes, we know that very well from all the other posts.

    We all know that very well too. Other than a few tricks like grill blocking, tire pressure, speed, etc, there seems to be very little we can do to mitigate the loss in those conditions. Hopefully the Toyota engineers will take this into consideration to see if they can increase efficiency in cold/wet weather in the future.
    But rehashing the issue here every other month isn't going to help your situation. If you have not, I would suggestion calling/writing Toyota with your complaint. I would also suggest selling the car as it seems to bug you quite a bit. No need to hang on to something that seems to be "driving" you crazy.
     
    #6 spiderman, Mar 8, 2010
  7. qbee42

    qbee42 My other car is a boat

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    The Prius is optimized for low emissions, and low emissions require heat. Good mileage is only a happy side effect.

    With the TDI, on the other hand, emissions are only as good as they need to be to sell it legally.

    Tom
     
    #7 qbee42, Mar 8, 2010
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  8. E-GINO

    E-GINO Active Member

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    In rain conditions, due to the increased density of the air and tyres friction on the wet concrete, all veihicles suffer some increase of fuel consumptions. In my opinion, what in the Prius make worse the difference between "nice weather" and "rainy and cold weather", is the heater, which may force the ICE to stay running even if not needed. Also cold and humidity may mist over the car windows, so you may have to turn on the A/C for defogging, with a further consumptions increase. Unfortunately, we miss the heat pump A/C, which should be available in the next Plug-In Prius.
    Regards
    Igino
     
    #8 E-GINO, Mar 9, 2010
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