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Tire Pressure and Cold Temp

Discussion in 'Gen 2 Prius Main Forum' started by bravery, Nov 3, 2006.

  1. bravery

    bravery New Member

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    Since it has starting getting colder here my tire pressure light is on when I first start my car in the morning. Then in about 15 minutes it goes off. Is it normal for the tire pressure to be low due to colder tempures or do I need to get my sensors checked?
     
    #1 bravery, Nov 3, 2006
  2. efusco

    efusco Moderator Emeritus
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    Tire pressure will drop about 1psi for every 10 degree temp drop. It's certainly possible that one or all are lower than the threshold for the TPMS, then when the tires warm with driving the sensor goes off.

    I'd check the cold temp pressures to see where you are. Good idea to juice them up to whatever pressure you're comfortable with to do what you can to minimize the cold weather MPG hit.
     
    #2 efusco, Nov 3, 2006
  3. Rangerdavid

    Rangerdavid Senior Member

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    I check mine first thing in the morning when they're cold. I keep them at 42-40. When it first turned cold here, my light come on as well. Just check 'em at least once a week, best time, IMO, is in the morning before you have driven anywhere. :lol:

    Good Friday to all...... :D :D
     
    #3 Rangerdavid, Nov 3, 2006
  4. sub3marathonman

    sub3marathonman Active Member

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    I've just had that happen here in Florida with the first "cold" weather. I guess the tires were right on the border of turning on the light.

    It did turn out that the pressure was about 28 psi, which is about 20% lower than the 35 psi called for in the front tires. So I guess the system is working as it should. Also, the light never went off, even driving for about 9 miles.

    I did refill them to the 41 psi, 39 psi that people recommend.
     
    #4 sub3marathonman, Nov 3, 2006
  5. john1701a

    john1701a Prius Guru

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    <div class='quotetop'>QUOTE(bravery @ Nov 3 2006, 06:25 AM) [snapback]343101[/snapback]</div>
    Your PSI has likely been well below the recommended minimum (35/33) for quite some time now... which acclerates tire wear, lowers MPG, and increases the likelihood of an accident.

    The cold caused the threshold to be exceeded, hence the light coming on. It shuts off after the air inside warms up, but your tires are still in need of air right away.

    This is one benefit of running higher PSI routinely. Forgetting to check often enough is a very common problem. More air available from the start helps.
     
    #5 john1701a, Nov 3, 2006
  6. galaxee

    galaxee mostly benevolent

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    don't check your sensors before you check your tire pressure!

    tires warm up as you drive, hence the light going off. sounds like you're right on the edge of the warning threshold. check your tire pressures, inflate accordingly, and reset your tpms. good time to check your spare tire pressure as well. seasonal changes bring about tire pressure changes.
     
    #6 galaxee, Nov 3, 2006
  7. Rangerdavid

    Rangerdavid Senior Member

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    <div class='quotetop'>QUOTE(galaxee @ Nov 3 2006, 03:23 PM) [snapback]343421[/snapback]</div>

    Excellent suggestion Galaxee!! I had not even thought about the spare!! B)
     
    #7 Rangerdavid, Nov 3, 2006
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