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Snow Tires - Impact On MPG (Real And Reported)?

Discussion in 'Gen 2 Prius Main Forum' started by jyl, Dec 22, 2006.

  1. jyl

    jyl New Member

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    I just got a set of snow tires installed on the 07 Prius.

    Cheap black steel wheels, with 195/65-15 Bridgestone Blizzak REVOs. Inflated to the same 42 psi F/40 psi R that the stock tires were using.

    I am curious what this might do to my MPG. Both the real MPG and - since the tires are 195 not the 185 of the stock tires - the reported MPG?

    Any similar experiences?
     
    #1 jyl, Dec 22, 2006
  2. jyl

    jyl New Member

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    <div class='quotetop'>QUOTE(John L. @ Dec 22 2006, 03:38 PM) [snapback]365848[/snapback]</div>
    I guess I should be more clear.

    I realize that the stock and snow tires have different diameters.

    Stock Goodyear Integrity 185/65-15 diam 24.4" rev/mile 855

    Snow Bridgestone REVO 195/65-15 diam 25.0" rev/mile 833

    So from a purely "geometric" point of view, the larger tires could cause my "reported" speed and MPG to be overstated by 855/833 = 2.6%.

    But is it more complicated than that? Do the larger tires make the car less, or more, efficient?
     
    #2 jyl, Dec 22, 2006
  3. bugmenot

    bugmenot New Member

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    I think that since you are driving on snow, you shouldn't worry about the gas you might save. Your life is probably a bit more important. Don't get carried away with MPG.
     
    #3 bugmenot, Dec 22, 2006
  4. kdxzknight

    kdxzknight New Member

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    I have installed the 185/65X15 tires (Michelin Ice) on my 07 Touring Prius and have now put 2500 plus miles on them. I have only noticed about 1 mpg difference. However it is getting colder up here in the Northeast and I feel that is mostly what is causing the loss in mpg. I still seem to average 46-47 mpg with mostly highway driving at 70-75 mph.
     
    #4 kdxzknight, Dec 22, 2006
  5. stanleyjohn

    stanleyjohn New Member

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    I installed my steel wheel with michelin x-ice tires a week ago and have seen a small increase in mpg so far.No winter so far here in ct so will see if snow and ice brings gown the mpg.
     
    #5 stanleyjohn, Dec 23, 2006
  6. jayman

    jayman Senior Member

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    Compared to the "all season" Michelin Harmony tires I run, I took a pretty big hit when I put on the new Goodyear Nordic studded snow tires back in November. No difference in city fuel economy that I could determine, but on the Trans Canada a given stretch at the same 105 km/h, I could expect 5.2 l/100km from the Harmony.

    With the studded Nordic, try 6.5 l/100km. So the Harmony was 54 mpg and the studded Nordic is only 44 MPG. Though with the much better snow and especially ice traction, I could care less how much lower my winter highway fuel economy is. As another poster commented, Beats ending up in a ditch somewhere.

    FYI, the Goodyear Nordic is only available at Canadian Tire. In the EU it's known as the Goodyear Ultra Grip 500:

    http://eu.goodyear.com/home_en/tires/repos...p?page=benefits

    I'm out of here, off to the hobby farm. See you in January!
     
    #6 jayman, Dec 23, 2006
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