Inflation pressure touring tires?

Discussion in 'Gen 4 Prius Main Forum' started by tucatz, Jan 7, 2017.

  1. RCO

    RCO Senior Member

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    I'd like to hear your definition of "myth" because laws of physics ain't mythology. (n)
     
  2. narf

    narf Active Member

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    Not a myth at all. The factors that define the size of the contact patch include the weight the tire supports, the tire pressure, and to some extend the sidewall stiffness. Since the sidewalls provide some support, the relationship between pressure and contact patch size isn't linear, but upping the pressure by 25% will decrease the footprint significantly, and a smaller footprint does result in longer stopping distances.
    As a side note, autocrossers will run very high tire pressures because the high cornering loads tend to deform the tires alot in turns, and the high tire pressures counteract the high cornering loads.
     
  3. RCO

    RCO Senior Member

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    Crazy! I never knew Prii were used for autocross in USA. :ROFLMAO:
    Your logic is fair as far as it goes, but it's not for me to point out its flaws.
    On the linear scale between Sensible and Foolish your idea is way off centre.
     
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  4. narf

    narf Active Member

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    Never autocrossed a Prius, my autocross "cars" were an MX5 Miata and a DFM 125cc shifter kart.
     
  5. RCO

    RCO Senior Member

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    Then surely the excesses you apply to those cars are unnecessary on a car that was never designed for sporting performance. I can't see your insurers being swayed by your argument either and betting you're not about to tell them your tyres are inflated that high.
     
  6. ETP

    ETP 2021 Prime(Limit),Highlander HYB Plat,B52-D,G,F,H

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    I ran 51 PSI in my Honda Hybrids but I only use 42PSI in my two new Touring's. 42PSI gives me outstanding tire wear and great MPG. Above 44PSI you get impact blow out possibilities on a pot hole road. At 51PSI I lost control of my Honda for a moment on a pot hole road. Immediately went to 44 PSI.

    I would never run 32 PSI in these tires as they will wear out too quick. But that is just me only and does not reflect the views of this TV station.

    Also after 6 years you need new tires anyway.
     
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  7. Mendel Leisk

    Mendel Leisk Sand Pounder

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    You mean due to age? Our michelin pilots had their 8th birthday in Feb, I'm monitoring them. Such low mileage though, and they spend winters in garage, cleaned and under UV resistance tire cover, so maybe that helps.
     
  8. RCO

    RCO Senior Member

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    I understand the rubber used constantly leeches out volatile chemicals to atmosphere which degrades the tyre's integrity. That's the main problem AFAIK.
     
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  9. WilDavis

    WilDavis Senior Member

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    …it has been my experience that Michelin tyres are outstanding, and perform superbly, unfortunately their tread outlasts their sidewalls, and I noticed on my last set of EnergySavers, fine cracks had started to appear in the sidewalls (on all of them) after about 60,000+ miles! :eek::(
     
  10. RCO

    RCO Senior Member

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    ... and what age were they when they cracked?
     
  11. yeldogt

    yeldogt Active Member

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    You should not over-inflate tires. Max is just that ..max .. it's not the recommended pressure. The tire and wheel are designed to work together ... without the proper pressure this will not occur. Overinflation will stiffen the tire, restricting tread movement and its ability to maintain contact. It can be very dangerous -- especially after the tire ages and the tread rubber stiffens.

    One of my drivers gets 60+ mph -- with both the Gen 3 and 4's .. and they all have the 17'

    ... I get get close to 60 on the 4 ... I think 56 was my best typical high with the 3. This occurs on flat roads -- when I'm driving out to the weekend places .. so not supper high speed .. normally some traffic.

    Once in service -- I keep my tires for 5 years. That's it .. after 5 years .. gone. I just switched out one of my SUV's w 1/2 tread remaining. An old tire is more dangerous vs one nearing the bars .. by a large margin. Take a fingernail and push on a 5 year old tire and again on a new one ...

    Running with high pressure is foolish ...
     
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  12. ETP

    ETP 2021 Prime(Limit),Highlander HYB Plat,B52-D,G,F,H

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    6 years is the recommendation to look for new tires. Generally nails and razor blades prevent me from ever getting to 6 years or 60K.

    Your life is worth more that a set of tires.

    How Old - and Dangerous - Are Your Tires?

    Carmakers, tire makers and rubber manufacturers differ in their opinions about the lifespan of a tire. The National Highway Traffic Safety Administration (NHTSA) has no specific guidelines on tire aging and defers to the recommendations of carmakers and tire manufacturers. Carmakers such as Nissan and Mercedes-Benz tell consumers to replace tires six years after their production date, regardless of tread life. Tire manufacturers such as Continental and Michelin say a tire can last up to 10 years, provided you get annual tire inspections after the fifth year.
     
  13. RCO

    RCO Senior Member

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    UK is very focused on what it calls Health & Safety regulations which requires business premises to be checked by a suitably qualified individual(s) to make a Risk Assessment. When assessing tyre size storage premises, proper ventilation to outside air is essential, because, in confined spaces the vapours given off can be to toxic to humans.
     
    #33 RCO, May 24, 2017
    Last edited: May 24, 2017
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