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Tire Upgrade

Discussion in 'Gen 2 Prius Accessories & Modifications' started by nyprius, Jun 26, 2006.

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  1. bobdavisnpf

    bobdavisnpf Member

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    <div class='quotetop'>QUOTE(Dimak @ Jul 10 2007, 12:40 PM) [snapback]476298[/snapback]</div>
    I would use 205's but not 15's. I don't think you'll improve performance on a 15x6 inch rim with a wider tire. You may get a little better straight-line takeoff and braking, but your evasive-action and cornering stability will be worse than with a narrower tire like the 195/R15.

    The basic problem is the mush factor: there is just too much ballooning out from the narrow little rim, and it has to make it all the way out to the pavement - about 5 inches of air. The wider section width means you have that much more sidewall mushing around between the wheel and the road. A narrower section width means less mush, since the sidewall takes more of a straight "path" to the outer edge of the tire.

    A 16x7 or 17x7 - or even 17x7.5 - will dramatically reduce the amount of sidewall needed to get the same section width. This is where you improve evasive-action and cornering stability.
     
    #161 bobdavisnpf, Jul 10, 2007
  2. dkit

    dkit Junior Member

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    Thank you.
     
    #162 dkit, Jul 10, 2007
  3. AOV

    AOV New Member

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    Thank you for all that information about upgrading the tires....my main concern is safety on the road. Planning a trip to Florida in a week, this time of year there are many torrential downpours there - their rainy season, and I have been through quite a few of them in a 1994 Toyota Corolla - it did well in it. Yet, I felt that the standard tires that are on the Prius now, probably would not do too well in that kind of rain. I am carrying precious cargo - my daughter and mom, and on the way back to New York, also my father will join us. So, safety is my number #1 concern. Will be looking into those Goodyear TT (195/60) that you recommended.
     
    #163 AOV, Jul 11, 2007
  4. AOV

    AOV New Member

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    <div class='quotetop'>QUOTE(nyprius @ Jun 27 2006, 11:55 PM) [snapback]277872[/snapback]</div>
     
    #164 AOV, Jul 13, 2007
  5. AOV

    AOV New Member

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    <div class='quotetop'>QUOTE(nyprius @ Jun 27 2006, 11:55 PM) [snapback]277872[/snapback]</div>
    After reading about your research and what other had to say as well....I have decided to upgrade to the Goodyear Tripletread 195/60R15's. I am going to be on the road a lot this summer, mostly south and the torrential downpours at this time of year are practically daily (especially in the Tampa, Fl. area). I have replaced/upgraded tires all my life, but never for a Prius. Had a question about the replacement of the tires. After reading the manual....where does the tire pressure warning valves and transmitters come into play here? and does one have reset the tire pressure warning switch after its all said and done?

    <div class='quotetop'>QUOTE(nyprius @ Jun 27 2006, 11:55 PM) [snapback]277872[/snapback]</div>
    After reading about your research and what other had to say as well....I have decided to upgrade to the Goodyear Tripletread 195/60R15's. I am going to be on the road a lot this summer, mostly south and the torrential downpours at this time of year are practically daily (especially in the Tampa, Fl. area). I have replaced/upgraded tires all my life, but never for a Prius. Had a question about the replacement of the tires. After reading the manual....where does the tire pressure warning valves and transmitters come into play here? and does one have reset the tire pressure warning switch after its all said and done?
     
    #165 AOV, Jul 13, 2007
  6. nyprius

    nyprius Member

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    <div class='quotetop'>QUOTE(Dimak @ Jul 10 2007, 03:40 PM) [snapback]476298[/snapback]</div>
    I suggest 205/60R15 or 195/60R15. The 205/65R15 is too tall for the Prius. Revolutions per mile are 821 versus 855 for the OEM 185/65R15. This is a 4% difference from the OEM. It will cause speedometer under-read of roughtly 2%, making speeding tickets more likely. Plus you'll increase the risk of hitting the wheelwell. the 205/60R15 has RPM of 846. It will slightly correct inherent Prius over-read and bring you close to actual speed. 205/60 and 195/60 have the closest RPMs to the OEM tire, without changing rims.

    A 205/60R15 is fine on a 6 inch rim. The 205/60 can be used with a 5.5 to 7.5 inch rim. You might be better off with a 195/60 though. This calls for a 5.5 to 7 inch rim. It would have less balloning, as another poster mentioned. However, balloning probably would not be much of an issue on the lower 205/60 (versus the 205/65). Several people on PC have put 205/60R15s on their Prius and say they work fine.

    Personally, I don't think it's necessary to change the rims on the Prius. Many people have put 195 tires on the 6 x 15 inch OEM rims, including me, and not had a problem. In my case, the tire upgrade resulted in a massive improvement in performance. Most of this was probably due to the higher quality tires. But I'm sure the wider tire also played a role. The OEM size for the Australian Prius is 195/60R15. It wouldn't be specified unless it was fine for the car.

    However, if you like the look of taller rims with lower profile tires, as many cars have these days, then spend the money. The taller, wider rim with lower, wider tires will hold the road better, but probably provide a rougher ride.
     
    #166 nyprius, Jul 16, 2007
  7. Boo

    Boo Boola Boola Member

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    <div class='quotetop'>QUOTE(nyprius @ Jul 16 2007, 12:50 AM) [snapback]479451[/snapback]</div>
    NYPrius,

    I have always appreciated your thoughtful posts, especially those regarding replacement tires, and am in complete agreement with your opinion about the TTs (my own experience with the TTs is that they are the best tires I have ever had, and it's hard for me to even imagine that there's a better all around tire out there).

    Because of that, when I noticed in one of the BT Tech Stiffening Plate threads that you were considering buying the plate, I was really looking forward to hearing your opinion about the plate. However, I haven't found a subsequent post by you about the plate (maybe I missed it, which would be easy to do given the length, acrimony, etc. of those threads). Did you ever buy and install the plate? If so, what's your opinion of it?

    -- Boo (fellow NY Prius owner)
     
    #167 Boo, Jul 20, 2007
  8. nyprius

    nyprius Member

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    <div class='quotetop'>QUOTE(Boo @ Jul 20 2007, 06:25 PM) [snapback]482489[/snapback]</div>
    Hi Boo,

    Thanks for your feedback on my posts! Maybe I get a little obsessive about my car. That's why I do all the research on tires. But I think that's a healthy obsession! If it helps others, great!

    I was seriously considering buying the BT stiffening plate, mainly because so many Prius owners say it greatly improves handling. I may still buy it. But I don't feel a sense of urgency the way I did with the tires. It seems highly likely that upgrading the tires will do much more to improve handling than adding the stiffening plate. But I don't know for sure since I don't have the plate.

    I asked a technical question on the long BT stiffening plate thread that never got answered. So I put buying the plate on hold. I was having a hard time understanding how the plate could improve handling. Why was increasing rigidity on that particular part of the frame going to make a differnce. Also, it seemed the bolt holes for the plate were designed for smaller, weaker bolts to support a flimsier piece of metal. Would narrow weak bolts hold the stronger plate well. All the emphasis on not overtightening the bolts seemed to highlight the fact that the bolt holes we not designed for the level of stress the plate would apply. But I haven't heard of bolts snapping off once the plate is installed correctly. So maybe it's not an issue.

    What I'd really like to do is test drive someone's Prius that has the plate and see if I notice a difference. The mechanic at my Toyota dealer didn't think the plate would do anything. But there are lots of owners who say it does. So I'd probably err on the side of trusting the owners. Maybe I'll buy the plate. But with the 195/60 TT's, my Prius handles very well. So I don't feel a large need to improve handling more.

    All the best, Frank
     
    #168 nyprius, Jul 20, 2007
  9. Boo

    Boo Boola Boola Member

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    <div class='quotetop'>QUOTE(nyprius @ Jul 20 2007, 11:31 PM) [snapback]482631[/snapback]</div>
    Hi Frank,

    I haven't put the TTs on my Prius yet, but will probably do so soon. As much as I love the TTs, I've had a hard time accepting the thought of throwing away the perfectly good (my Prius only has 1000 miles on it), albeit, bad performing Integrities.

    After I install the TTs, I may install the stiffening plate. If I do, I'll be sure to let everyone know what difference, if any, I perceive the stiffening plate to make, and I will also gladly let you do a long test drive of my car (I live in Stuyvesant Town) if you want to test the plate yourself.

    Anyway, time to go install the PriusChat Accessories Shop's body side moldings on my car (I already put on bumperdefender.com's 2" full-width, color-matched front and rear bumper guards, which, for their intended purposes, I like and recommend as much as the TTs).

    Cheers,

    Tom
     
    #169 Boo, Jul 21, 2007
  10. Rae Vynn

    Rae Vynn Artist In Residence

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    Yesterday, while driving home from work, I hydroplaned.

    I have NEVER hydroplaned before.

    These OEM tires are HISTORY!! :angry:

    I am getting the Michelin Hydroedges, as soon as they go on sale (next month, Costco).
     
    #170 Rae Vynn, Jul 22, 2007
  11. nyprius

    nyprius Member

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    typo
     
    #171 nyprius, Jul 22, 2007
  12. nyprius

    nyprius Member

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    <div class='quotetop'>QUOTE(Boo @ Jul 21 2007, 10:26 AM) [snapback]482746[/snapback]</div>
    Hi Tom,

    If you put on the stiffening plate, I'd love to take you up on your offer for a test drive. The bumber guards sound great, especially if you park on the street in NYC! I've got a polybra on the front and back bumpers. They work well, but I think the bumper guards would provide more protection. I put black ding bars on the sides of my car. They make it look sleeker and do a great job of preventing dents from people opening doors on my car.

    In my experience, the TT's are excellent. I don't think anyone would go wrong with them. But there are many other great tires for the Prius.

    I replaced the Integrities when they had 25,000 miles on them. Knowing what I know now about how bad they are and how good other tires are, I would replace the Integrities on day one if I had to do it all over again. I bet someone would give you credit for Integrities with 1,000 miles on them. Good luck!

    I would go for the tire upgrade, even if the Integrities are new. $500 is a small price to pay (in relation to the price of the car) given the massive improvement in performance you'll achieve. Why not have excellent tires on the car during the best part of it's life.

    Please let me know if you put on the BT plate...

    Thanks, Frank
     
    #172 nyprius, Jul 22, 2007
  13. hesterdendy

    hesterdendy New Member

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    <div class='quotetop'>QUOTE(nyprius @ Jun 26 2006, 10:46 AM) [snapback]276822[/snapback]</div>
    Thanks for the interesting post on all-season tires!

    Does anyone have specific recommendations on dedicated snow tires and rims?

    <div class='quotetop'>QUOTE(Three60guy @ Jun 28 2006, 01:19 PM) [snapback]278138[/snapback]</div>
    I'm unable to download this file for some reason. Is there another place to view it or can someone send it to me direct?

    TIA
     
    #173 hesterdendy, Aug 10, 2007
  14. Boo

    Boo Boola Boola Member

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    <div class='quotetop'>QUOTE(hesterdendy @ Aug 10 2007, 10:10 AM) [snapback]493497[/snapback]</div>
    I do not have personal experience with snow tires in the past 25 years, but FYI:

    The Michelin X-Ice is the highest rated snow tire in Consumer Reports' last test of snow tires. PriusChatters as well as TireRack customers also give this snow tire high marks. TireRack.com sells the 185/65/15 size for $81 (USD).

    P.S. What "Other Hybrid" do you drive?
     
    #174 Boo, Aug 10, 2007
  15. mmoore

    mmoore New Member

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    Thanks for the excellent info nyprius - I just discovered Priuschat while looking for new tires. You seem to have done extensive research on this, so we would appreciate your input on this. Since we live on a wet, mountainous, one lane road with blind curves that has caused us more than once to slam on the brakes going downhill around a curve (to avoid uphill speeders, usually guests of someone who just don't know better) our priority is the very best tire we can find to help us stay dent free in these situations. We have decided on the Michelin Pilot Exalto A/S and would go for the 205/60-15 except for the comment you made about the slightly higher tire perhaps not cornering as well, and the tread on the road not actually being wider. If it turns out that the Exalto 205 does have a slightly wider footprint than the 195 (unlike the Goodyears you have) do you think there would be any real benefit to them, or are we just being obsessive? In our case, stopping even 1/2 inch sooner could make a difference and the loss of mpg isn't an issue. Thanks in advance for any thoughts you might have on this.
     
    #175 mmoore, Sep 25, 2007
  16. Boo

    Boo Boola Boola Member

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    <div class='quotetop'>QUOTE(White Lightning @ Sep 25 2007, 02:03 PM) [snapback]517476[/snapback]</div>
    IMO, as a general matter, the wider footprint will not perform as well (stopping, handling, hydroplaning) under wet conditions, but should perform better under dry conditions.
     
    #176 Boo, Sep 26, 2007
  17. mmoore

    mmoore New Member

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    <div class='quotetop'>QUOTE(White Lightning @ Sep 25 2007, 10:03 AM) [snapback]517476[/snapback]</div>
    Thanks for the input BOO. That makes sense now that you mention it, so for our wet-road purposes the narrower tire is the better option.
     
    #177 mmoore, Sep 26, 2007
  18. Boo

    Boo Boola Boola Member

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    <div class='quotetop'>QUOTE(White Lightning @ Sep 26 2007, 02:17 PM) [snapback]518002[/snapback]</div>
    Of course I have no scientific data or test results to back this up. Just makes sense to me as a general matter based on anecdotal personal experience --- e.g., the only times I've experienced serious hydroplaning is when driving sports cars with their wider than average tires.

    Sounds like your choice of Michelin Pilot Exalto A/S is a great one for your purposes. Top Rated by Consumer Reports and TireRack customers for performance all-seasons, and liked by a lot of PriusChatters (though its 45,000 miles wear warranty is kind of average).
     
    #178 Boo, Sep 26, 2007
  19. nyprius

    nyprius Member

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    <div class='quotetop'>QUOTE(White Lightning @ Sep 25 2007, 02:03 PM) [snapback]517476[/snapback]</div>
    Thanks for your feedback on my post White Lightening! In terms of improving performance, I think tire quality is more important that tire size. As Boo said, the Exalto is a high rated tire and seems like it would do a good job under the conditions you described. Being high performance instead of regular all season, it won't last as long (ie: 45,000 mile warranty). But that's a pretty small price to pay for better traction.

    While tire quality may be more important than tire size, tire size clearly makes a difference too. All things being equal, the wider tire holds the road better under most conditions, except perhaps loose snow and deep water. Virtually all high end cars use wider tires. They wouldn't do this if it didn't improve performance (and not just under dry conditions).

    Re tire size, I'd go for the 195/60 or 205/60, instead of the 195/65 or 205/65. The 65's are higher and distort RPM too much. Plus the higher tire usually has narrower tread. And it's more likely to hit the wheel well. Re the 205/60, many people on PC have 205/60's on their cars. I haven't seen one complaint related to this tire size. So it's probably fine.

    I lean toward the 195/60 though since it's the design width for the car (ie: OEM in EU and Australia, option in US and Japan). The 195/60 is slightly lower than the 205. So on several tires, such as the TT, it has the same or nearly the same tread width. Also, since it's slightly lower, it would tend to handle a little better. This might offset the improved handling of the wider, but higher 205.

    Bottom line: there probably isn't much difference between the 195/60 and 205/60 in handling. The key is getting a high quality tire. Replacing the low quality Integrity is key. Upgrading from the skinny 185 is also a good idea.
     
    #179 nyprius, Sep 28, 2007
  20. mmoore

    mmoore New Member

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    <div class='quotetop'>QUOTE(nyprius @ Sep 27 2007, 09:34 PM) [snapback]518881[/snapback]</div>
    Thanks for taking the time to respond, nyprius! I'm going for the Exalto 195/60. I very much appreciate how much I have learned in the last 4 days since I discovered priuschat.com - and getting what I consider the best possible advice from the prius experts has helped much more than what I was able to glean from online research and talking to tire dealers. This is a great resource, and it looks like driving our 2005 Prius is going to become even more fun! I look forward to learning more, and giving something back when the time comes.
     
    #180 mmoore, Sep 28, 2007
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