Does heat - like cold - mean tires need air?

Discussion in 'Gen 2 Prius Main Forum' started by Freedom, Aug 13, 2020.

  1. Freedom

    Freedom Active Member

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    I live in New England. In Winter when we have a really cold snap, as soon as it warms the tire air light comes on. Have to go get air. Normal, used to that.

    This summer has been the hottest on record. We have had 3 heat waves, 4 days each. EVERY TIME the first overnight drops below 72 degrees, next morning the tire air light comes on, and I have to go get air. I am not used to getting air in the tires every 3 weeks in Summer. Do I have a tire leak? Or is this normal, just the flip of Winter and I need to adjust? Thanks.
     
  2. bisco

    bisco cookie crumbler

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    pressure goes up with heat, down with cold. maybe you just need to put a little extra in. i keep mine at 42/40 f/r, and haven't seen the light.
    but it would be a good idea to get a decent gauge and track the pressures
     
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  3. sam spade 2

    sam spade 2 Senior Member

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    Any "seasonal" need to add air ONLY because of temperature differences occurs at, or a few hours after, the coldest point in the cycle.
    Not the next day or the next week.
    And never when the temp is and has been rising.

    It would make this investigation a LOT easier if you had taken note of which tire has been requiring the air.
     
  4. PriusCamper

    PriusCamper Senior Member

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    When you got your last set of tires did they do maintenance or replacement on air pressure sensors?
     
  5. Freedom

    Freedom Active Member

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    Wow. On the driver's door, it says 35 Front, 33, Rear. You keep it higher? Interesting.

    Well the sensor only says tires need air, it does not say WHICH tire. The coldest point would be the overnight low, so when I use the car in the morning, that's when the light is on.

    I had to replace 1 tire in April, 2 nails in it. They put a new sensor on that one, at that time.

    I've fixed the air, now to see what happens going forward.
     
  6. PriusCamper

    PriusCamper Senior Member

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    Well, that could be the source of your problem... Time to re calibrate the system and see if that solves it: Reset Tire Pressure Monitor System? | PriusChat

    As for tire pressure, I run my Low Rolling Resistance Ecopia at 47 up front and 45 in the back. Makes a big difference with tire wear and boost MPG. But I live on West Coast of US and am mostly driving on quality built freeways... These tire pressures are not ideal for city driving or rural driving.
     
  7. Freedom

    Freedom Active Member

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    I reset every time I put air in. Which is regularly. And I did reset when I got the new tire and sensor.

    How do you keep your tire warranty with them over inflated? The tires would wear incorrectly over time.

    My longest trip is about 5 miles one way. I try to only use the car 3 days a week. Pandemic has made car use less than normal, though.
     
  8. bisco

    bisco cookie crumbler

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    i don't think you need to reset after filling. tire sidewall max is covered by warranty, but tire warranties are mostly fiction
     
  9. sam spade 2

    sam spade 2 Senior Member

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    Obviously. But the person who checks all 4 tires to see which one(s) actually need air certainly should know.
    Right ??
    It is good to make note of which ones actually DO need air.
    If it is always the same one.............
     
  10. PriusCamper

    PriusCamper Senior Member

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    Yeah, that's the balloon theory, which thinks a is so flimsy thin that over-inflating means the tire will be unable to hold it's shape and wear out faster and unevenly.

    Truth is my tires are rated to 60K miles and the last set I had lived their entire life at 47psi in front & 45psi in rear and guess what? I got 70K miles out of those tires and absolutely zero evidence of uneven wear.

    As I've said on here many times, the max tire pressure rating in the the mid 30's is for liability purposes in order to ensure that the dumbest most clueless driver that gets in an accident can't sue the tire company... And granted if you drive your car like it's a race car low tire pressure is a great way to get around a corner faster without sliding. But if you simply want to roll down the slow lane at 65mph and go as long as possible between getting your gas tank re-filled higher tire pressure is the way to go.

    Of course, it has to do with the roads you drive on. I always tell people to add a couple psi at a time and then back off a few psi once the traction loss becomes noticeable. For me and the roads I drive on that happened at 50psi.
     
  11. Freedom

    Freedom Active Member

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    Update to this story. Tire light came on again. Since I know which tire, I went to the tire place yesterday morning.

    Background: In MAY, I was in because the passenger front tire kept needing air. I was told it had 2 nails in it and could not be patched, so I bought a new tire and a new sensor. THAT SAME TIRE was the one leaking now. So I went in to the tire shop.

    Yesterday: Tech reported back to the shop owner that the leak is happening at the sensor. Back in May she put in a rubber neck sensor. Yesterday she replaced that, since it was leaking, with a metal neck sensor . . . so it matches the other 3. Wait a minute. The other 3 were part of the deal 2 years back when she put on the 4 new Nokia tires with 4 new sensors. So in May when she replaced the bad tire she put in a different sensor? I wasn't happy hearing this, but didn't comment. Because . . . then she goes on to say she had the tech test and the sensor on the driver's rear is dying, did I want that replaced? She said generally recommend replacing sensors every 4 years but nobody does that, folks just wait until it dies; and she adds, "your car is a 2008 so you are ahead of the game." To replace the dying one would cost me $115, I said forget it I'll wait. There was no charge for replacing the rubber neck one, as she said it was supposed to last 12 months or 12,000 miles and clearly it did not. As usual for me, once I was back home I thought it over and: Um, she's only seen my car for 2 years how the heck would SHE know if it was an original sensor? And in fact, she WOULD know it is a sensor she put in, just 2 years ago!

    The car is fine, working, all set. But the exchange at the end left me feeling like I really don't want to deal with this place again. I know I get that way when I don't understand enough to know what's happening. She had absolutely the best price on the Nokia tires when I bought them, I called and priced 4 places and she was $175 less than the next lowest, for the set of 4. Until yesterday I've been happy dealing with her and her shop. Now, I'm not so sure.
     
  12. Mendel Leisk

    Mendel Leisk Sand Pounder

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    You've now got 4 tires that are holding air? Do nothing for a while; fugedabout the sensors.
     
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