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195/60 vs 185/65 tires

Discussion in 'Gen 2 Prius Main Forum' started by plantz, Aug 30, 2007.

  1. plantz

    plantz Junior Member

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    Has anyone actually driven on the two different size (195/60/15 verus 185/65/15) tires that are the same brand/model/age back to back?

    All the comments I read talk about replacing old tires or changing brand/model. These factors could play a larger role than the size difference.

    The only fair comparison I've seen is at consumerreports.org. They looked at plus sizing that included larger wheels. That is, changing wheels and going from 185/65/15 to 195/60/16. They found barely any improvement in wet/dry braking, 2.5% improvement in emergency handling, 3% improvement in wet/dry cornering, and 5% improvement in ice braking. On the downside, hydroplaning was worse by 2%, ride comfort was worse by 23%, and snow performance dropped by 5%. (All my numbers are approximates from reading their graph.)

    These results all seem reasonable to me, although I'm surprised at the large decrease in "ride comfort" (which includes "ride" and "noise").

    I am planning to replace my Integritys with Michelin Primacy MXV4. (Costco is having an $80 off sale in my area through 9/2.) I'm not a "sporty" driver. Friends who ride with me sometimes remark on my cautious driving technique. And I'm at an age (68) where comfort is significant. So I'm inclined to go with the stock 185/65/15 size. My thought is that just switching to the Michelins will bring a large increase in safety (due to better traction and handling), but that the size change would add very little more to the safety while causing a large decrease in comfort. Actually, the wider tires decrease safety in a few situations; everything in life is a compromise.
     
    #1 plantz, Aug 30, 2007
  2. rudiger

    rudiger Active Member

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    <div class='quotetop'>QUOTE(plantz @ Aug 30 2007, 12:15 PM) [snapback]504334[/snapback]</div>
    This doesn't have anything to do with the question but what is the total price you'll be paying for tires (less the $80 off)?

    The reason I'm asking is that it seems that most (if not all) of the Costco stores in other states have $60 off instead of $80 and I was wondering what was the reason (like maybe to offset a higher individual tire price so the net tire price is exactly the same as the other Costco store tire prices).
     
    #2 rudiger, Aug 30, 2007
  3. Syclone

    Syclone Member

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    <div class='quotetop'>QUOTE(plantz @ Aug 30 2007, 12:15 PM) [snapback]504334[/snapback]</div>
    I switched from the "unintegritys" to 195-60-15's (Michelin MXV4+) about a year ago.

    Summary:

    Better ride
    quieter
    slightly better gas mileage
    much better handling
    much better grip on the road
    slight decrease in speedo accuracy

    Seriously, the Integrity's are crap tires. They ride bad, look bad, feel bad.

    Other than that, they are fine tires. B)

    Forgot to add - you can mount tires up to 205 size on the stock rims.
     
    #3 Syclone, Aug 30, 2007
  4. hyo silver

    hyo silver Awaaaaay

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    It sounds to me like you've answered your own question. If a wider tire decreases road comfort so much, and that's what's most important to you, then stick with the stock size. It's certainly not worth buying new wheels and tires. Regardless of the size, a good quality tire will be a huge improvement over the Integrities.
     
    #4 hyo silver, Aug 30, 2007
  5. Rae Vynn

    Rae Vynn Artist In Residence

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    <div class='quotetop'>QUOTE(hyo silver @ Aug 30 2007, 09:41 AM) [snapback]504345[/snapback]</div>
    The stock wheels accept the 195/60/15s with no trouble. No need to change wheels.
     
    #5 Rae Vynn, Aug 30, 2007
  6. David Beale

    David Beale Senior Member

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    The tires I'm considering (Nokian WR) are not higher rated at the 195/60 - 15 size compared to the stock size. Same load rating. Slightly more rubber on the road.

    A larger tire will not generally have more susceptibility to hydroplaning than a smaller tire. If one report claims this, they didn't look closely enough at the tires. Inflation pressure can have quite an effect on hydroplaning. A larger tire should have the inflation pressure adjusted to compensate for the size difference if comparing the two sizes. Ditto in snow.

    In general, on ice, more rubber will give better traction. Again, adjusting tire pressure is necessary to properly compare tire sizes.

    As for my tires and going to Nokian WR tires, I am considering 205/60 - 15
    to get a higher load rating for better damage resistance on rough roads. Or I may just go stock size.
    As you say, there are always compromises. These tires are heavier, so handling and ride may decrease.
    The Nokian WR is an "all season" performance tire that works well in snow, rain, ice, and wears well on dry roads. My experience with other vehicles is that it is not noisy (used it on an RX-8 and the anti-Prius (2001 Pathfinder).

    Standing from one foot to the other trying to decide as well. ;) But on size only.
     
    #6 David Beale, Aug 30, 2007
  7. Sarge

    Sarge Senior Member

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    <div class='quotetop'>QUOTE(plantz @ Aug 30 2007, 12:15 PM) [snapback]504334[/snapback]</div>
    Assuming all else is equal (tread pattern, tread remaining, etc...) simply increasing the width of the tire would increase the contact patch, and therefore be slightly more susceptible to hydroplaning. The wisdom I have always heard is narrow tires are better for snow vs. wider tires, as they will tend to cut through the snow rather than roll over it. Again, assuming tires are equal quality.
    <div class='quotetop'>QUOTE(plantz @ Aug 30 2007, 12:15 PM) [snapback]504334[/snapback]</div>
    'Ride comfort' is rather subjective. A more accurate description would be that lower profile tires transmit more road bumps, cracks, etc... to the passengers and give a "stiffer" ride as a result of less rubber between the rim and the road. Some people like this characteristic, others don't. From the sound of it, this reviewer falls into the latter category.
    <div class='quotetop'>QUOTE(plantz @ Aug 30 2007, 12:15 PM) [snapback]504334[/snapback]</div>
    Indeed! ;)
     
    #7 Sarge, Aug 30, 2007
  8. hyo silver

    hyo silver Awaaaaay

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    <div class='quotetop'>QUOTE(Rae Vynn @ 2007 Aug 30 9:45 AM) [snapback]504348[/snapback]</div>
    You're right. I was thinking of the study, cited by the original post, that included both wheels and tires. Not only is that not worth it, it's not necessary. Thanks for clarifying.
     
    #8 hyo silver, Aug 30, 2007
  9. apriusfan

    apriusfan New Member

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    <div class='quotetop'>QUOTE(plantz @ Aug 30 2007, 09:15 AM) [snapback]504334[/snapback]</div>
    As others have posted, to a large degree, you have answered your own question. The general trend in tire replacement is that if an owner goes with a replacement tire other than what was fitted at the factory, it is because they are not satisfied with the "performance" of the original tire. There can be any number of "performance" characteristics that are important to the individual; you have indicated comfort is a priority for you.

    <div class='quotetop'>QUOTE(plantz @ Aug 30 2007, 09:15 AM) [snapback]504334[/snapback]</div>
    Fortunately, there are other choices (beyond the OEM tires) for tires in the 195/60-15 size range. Tirerack has conducted a number of road tests of tires and published the results on their site (tirerack.com).

    <div class='quotetop'>QUOTE(plantz @ Aug 30 2007, 09:15 AM) [snapback]504334[/snapback]</div>
    Why do you believe that the change to Michelin tires will decrease ride comfort? Also, why do you believe that wider tires decrease safety? If your belief is based on the Consumer Reports test that you cited, that test only applies to the tire brand that was tested and not to any other tire brand.

    Presuming the Michelin tires you are considering have the same circumference as the OEM tires, you will be able to fit the Michelins to your car and have no problems with speedometer/odometer accuracy. I also don't think you will notice any difference in ride comfort (maybe an improvement with the Michelins, but not a decrease) by switching to the Michelins.
     
    #9 apriusfan, Aug 30, 2007
  10. priusenvy

    priusenvy Senior Member

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    <div class='quotetop'>QUOTE(Sarge @ Aug 30 2007, 10:21 AM) [snapback]504376[/snapback]</div>
    Wider tires are more susceptible to hydroplaning because the water has a long path to travel to evacuate. The contact patch should be mostly unchanged, since it's more dependent on tire pressure (tire pressure x contact patch = supported weight, which is constant), ignoring second-order effects like the stiffness of the tire carcass.

    It's not that simple. If you have soft snow that the tire can cut through to get to pavement, then narrow tires work better. But if you have firmer snow on top that you cannot cut through, then friction is maximized by snow-to-snow contact, and what you want is as much snow stuck to your tire contacting snow on the surface, which you get with a wider tire.
     
    #10 priusenvy, Aug 30, 2007
  11. Tideland Prius

    Tideland Prius Moderator of the North
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    <div class='quotetop'>QUOTE(plantz @ Aug 30 2007, 09:15 AM) [snapback]504334[/snapback]</div>
    If you want maximum ride comfort, I would suggest Goodyear Assurance ComforTred tyres.

    Going wider won't affect ride quality. It's the sidewall height (the fact that it's 60 not 65). A shorter sidewall height means better handling but also affects ride quality. Also tyre pressure plays a role. With the stock tyre, Toyota recommends 35/33. I have mine up 38/36 and it's a stiffer ride for sure.
     
    #11 Tideland Prius, Aug 30, 2007
  12. Syclone

    Syclone Member

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    <div class='quotetop'>QUOTE(Tideland Prius @ Aug 30 2007, 03:25 PM) [snapback]504438[/snapback]</div>
    Based on information from a couple of people that switched to comfortreds, the ride will improve, but you will take a 2 - 3 MPG hit.
     
    #12 Syclone, Aug 30, 2007
  13. plantz

    plantz Junior Member

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    Thank you everyone for taking the time to respond.

    <div class='quotetop'>QUOTE(rudiger @ Aug 30 2007, 09:31 AM) [snapback]504338[/snapback]</div>
    $112.99 for Primacy 185/65/15. The online price is $110.99; I think the additional $2 is for a Calif. tax. The $80 off coupon says its good only in California.

    <div class='quotetop'>QUOTE(hyo silver @ Aug 30 2007, 09:41 AM) [snapback]504345[/snapback]</div>
    Pretty much so. But I'm always open to others pointing out flaws in my thinking, especially before I've paid my money. :)

    <div class='quotetop'>QUOTE(apriusfan @ Aug 30 2007, 10:38 AM) [snapback]504387[/snapback]</div>
    I think you misread my original post. I don't think changing to Michelin will decrease ride comfort. The Consumer Reports test suggests that the 195/60/15 will be less comfortable than the 185/65/15. As someone else pointed out, that is probably due to the shorter sidewall.

    I agree that the Consumer Reports test only applies to the brand(s) they tested. Furthermore, results may vary on different vehicles. But I believe that their test is the fairest one I've seen so far. Most of us make these judgments based on (1) buying new tires that usually replace well-worn ones, then (2) inadvertently "testing" them because a deer runs in our path, we hit a water puddle or icy spot, another driver cuts us off, etc. Of course, each particular situation is different, and any test can only go so far toward predicting what will actually occur.

    Several people mentioned that I would not have to change wheels in order to use 195/60/15. Although that's the test that Consumer Reports did, I have no intention to do that. My take is that using the 195/60/15 (versus 185/65/15) on the same wheels would lower the percentage differences noted by Consumer Reports somewhat, but I don't believe anyone has done that side-by-side test. (Again, using the same tire brand/model, but just different sizes.)

    Again, thanks for all the thoughtful comments.
     
    #13 plantz, Aug 30, 2007
  14. priusenvy

    priusenvy Senior Member

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    <div class='quotetop'>QUOTE(syclone @ Aug 30 2007, 01:24 PM) [snapback]504489[/snapback]</div>
    With which tires have people not experienced a mileage hit? I took a 2-3 mpg hit with my 195/60-15 Goodyear TripleTreds.
     
    #14 priusenvy, Aug 30, 2007
  15. koa

    koa Active Member

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    I took a 3-4 mpg hit with 205/60X15 Michelin Pilot Exalto A/S.
     
    #15 koa, Aug 30, 2007
  16. Syclone

    Syclone Member

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    <div class='quotetop'>QUOTE(priusenvy @ Aug 30 2007, 05:16 PM) [snapback]504514[/snapback]</div>
    My experience with the switch to Michelins was that my mileage appeared to increase over the Integritys
     
    #16 Syclone, Aug 30, 2007
  17. Rae Vynn

    Rae Vynn Artist In Residence

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    I'm riding on about a 3 mpg hit, at 200 miles, but this is the first tank on the new tires. I expect that those 3 mpgs will return home, as soon as the "super new" is off the tires.
    After all, I got a MPG increase when the OEM tires were at about 800 miles.
     
    #17 Rae Vynn, Aug 30, 2007
  18. AOV

    AOV New Member

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    <div class='quotetop'>QUOTE(priusenvy @ Aug 30 2007, 05:16 PM) [snapback]504514[/snapback]</div>
    I have had mine for a couple months, did some long distance traveling...now about 5K on the Goodyear's TT and I too have seen about 2-3 mpg hit. Not happy with that, yet I would not go back.
     
    #18 AOV, Aug 31, 2007
  19. patsparks

    patsparks An Aussie perspective

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    <div class='quotetop'>QUOTE(plantz @ Aug 31 2007, 06:43 AM) [snapback]504513[/snapback]</div>
    If 195/60/15 have the same rolling circumference as 185/65/15 then the side wall is the same height.
    The only difference is the tread and overall width.
    If the tyre pressure is the same and the weight of the vehicle is the same then the contact patch of each tyre is the same size but the shape changes. The tyre contact patch is wider and shorter but no harder or softer as the tyre's internal pressure is the same. A wider contact patch will be affected more by road irregularities because it will hit more of them and the ones on the edge of the tyre are further from the pivot axis of the steering.
     
    #19 patsparks, Aug 31, 2007
  20. plantz

    plantz Junior Member

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    <div class='quotetop'>QUOTE(patsparks @ Aug 31 2007, 05:58 AM) [snapback]504830[/snapback]</div>
    They are not quite the same circumference. The sidewall of a 185/65 is 120.25 mm and for a 195/60 it is 117.00 mm. The 195/60/15 is 2.7% smaller in diameter, which could account for the slightly harsher ride some people have noted.
    You make a good point. I imagine that most comparison testing is done on smooth pavement. The roads where I live are definitely not smooth.

    Another issue is tire weight. Since the tread is the heavier part of a tire, a wider one will be heavier, thus increasing unsprung weight. This also increase ride harshness. In addition, I believe that it tends to reduce grip over bumps.

    The 185/65/15 on the Prius is narrow for a car of its weight. But I have a sense (perhaps naive) that the springs and shocks are tuned accordingly. I assume (again, perhaps naively) that the Touring model (which has wider tires) has a different spring/shock tuning.
     
    #20 plantz, Aug 31, 2007
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