1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Tire over inflation

Discussion in 'Gen 3 Prius Main Forum' started by Jonny Zero, Sep 10, 2012.

  1. The tire pressure on the side wall is for the tire installer, warning not to go beyond that pressure! However, all installer MUST exceed that pressure in order for the tire to seat on the rim. Somewhere around 44-50 is a good pressure if you want economy and longlife. Keeping the tire at the rec. door specs will give you a nice soft ride and premature wear.
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,710
    38,247
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Sorry, but I don't see that "implied implication" either. Guess we'll agree to disagree?
     
  3. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

    Joined:
    Apr 13, 2004
    15,140
    611
    0
    Location:
    South Puget Sound, WA
    Vehicle:
    2013 Nissan LEAF
    Model:
    Persona

    actually its normal to go up to 100 PSI to seat the tire bead but that is in a shop for a few minutes and has no bearing on what is recommended when driving down the road.

    unfortunately my tire expert is no longer with us but as a tire store manager, it was his recommendation that the max tire pressure printed on the sidewall is as i have stated on this thread.

    the reasoning for the wording "maximum recommended pressure" instead of "recommended pressure" is that the latter implies that there is an "optimum pressure" that might be more which can be untrue in certain climates and thus the wording is more a legal thing than a safety or performance thing. therefore the 44 PSI COLD pressure rating is there for the hottest weather you can expect to see so this pressure is completely safe if you are cruising Death Valley in July. for all others, it is more than safe and is the recommended tire pressure for best life and safety and handling
     
    Andyprius # 1 likes this.
  4. I'll go along with that.
     
  5. Jonny Zero

    Jonny Zero Giggidy

    Joined:
    Jun 22, 2012
    1,388
    351
    0
    Location:
    Austin, TX
    Vehicle:
    2012 Prius
    Model:
    Five
    One more thought - would higher pressures affect the operations of VSC, ABS, TRAC, etc?
     
  6. DaveinOlyWA

    DaveinOlyWA 3rd Time was Solariffic!!

    Joined:
    Apr 13, 2004
    15,140
    611
    0
    Location:
    South Puget Sound, WA
    Vehicle:
    2013 Nissan LEAF
    Model:
    Persona
    not really. some feel higher pressures makes TRAC more sensitive. i don t see that. inversely, if stuck somewhere i have seen the recommendation to remove some air from tires to get better traction which is something I DO NOT recommend unless you have a way to reinflate the tires after you get out of your predicament
     
  7. F8L

    F8L Protecting Habitat & AG Lands

    Joined:
    Aug 14, 2006
    19,011
    4,080
    50
    Location:
    Grass Valley, CA.
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    In theory it could but generally at higher speeds and rough surfaces. It is well established that tires can skip across imperfections in the road when tire pressure is so high that the tire cannot conform to those imperfections. Cold temperatures can cause the same problem. The design and compound will have a large effect on how much a tire skips.
     
  8. xs650

    xs650 Senior Member

    Joined:
    Jul 2, 2010
    4,539
    1,433
    9
    Location:
    Northern California
    Vehicle:
    2010 Prius
    Model:
    II
    Higher pressures will cause the tires to bounce a bit more on rough surfaces. I'm running in the low 40 psi range and hardly notice it, but the effect is there. If you did a before and after test at sticker pressure and 45 psi and tried braking hard as you cross some rough railroad tracks you would feel a little difference in the ABS. The difference isn't big and I wouldn't hesitate to run 45 psi if I felt like it.
     
  9. Jonny Zero

    Jonny Zero Giggidy

    Joined:
    Jun 22, 2012
    1,388
    351
    0
    Location:
    Austin, TX
    Vehicle:
    2012 Prius
    Model:
    Five
    So what I am hearing is ABS and TRAC may be more trigger happy due to tire skipping. Anything with the VSC? Would it affect the yaw rate reading and render the system less effective? (assumming the braking wheel still gets sufficient traction at the higher pressure, to make the yaw correction.)
     
  10. F8L

    F8L Protecting Habitat & AG Lands

    Joined:
    Aug 14, 2006
    19,011
    4,080
    50
    Location:
    Grass Valley, CA.
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Yes but different tires can cause the same effect because of differences in traction and tread suppleness. So a cheap tire or one with so so traction can cause the effect at lower pressures than say a tire with much better traction at higher pressures.
     
  11. jrb451

    jrb451 Junior Member

    Joined:
    Nov 2, 2010
    59
    6
    0
    Location:
    Conway, AR
    Vehicle:
    2010 Prius
    Model:
    IV
    Sounds like you had a good experience with the Michelins. Just curious why you would switch tires if this were the case. I didn't get that much wear out of my Bridgestones and am having these Michelins installed on my Prius tomorrow.