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Effy's avatar
Effy
Explorer II
Oct 24, 2013

tire pressure variance based on ambient temperature

Heading out for a trip tomorrow. Middle of the day and took the PSI cold. It's low - of course since we are in a bit of a cold snap. Currently it's 41 degrees and it's about 7 PSI below what it should be. So, obviously I plan to bring it back up to the correct PSI. However, my destination forecasted temperature will be 60+. Won't this cause an overinflation PSI when I check it there? How does one handle variances in ambient temperature? If I leave for Fla in winter and it's 30 here and 80 there, there will be a significant change in PSI. I would think over is better than under, but over isn't so good either. Is it? Am I over thinking this?
  • Overthinking? Yes.

    Tires pressures recommendations are based on averages, including minimum pressure when tires are cold, and higher pressure when tires are hot on a hot day. While the standard instruction is to check and inflate a cold tire, you can add a little to the recommended minimum pressure if checking on a hot day or while the tire is hot, or at 10,000 feet, or in the hot sun, etc. In other words, don't worry about slight changes. Under inflation is probably the worst thing to worry about.
  • The tires are designed to handle the variances in tire pressure caused by temperature.
    Look at it this way....suppose you are in a hot location and the outside temps is 100 degrees. You are carrying the maximum load so you inflate the tires to the sidewall max. Obviously once you hit the road, the tire temperature will increase, which will increase the tire pressure even more. Even tho this is above the max on the sidewall, it is not a problem and is still well within the tire design specs.
    As you know, under-inflation is what kills most tires.
  • I check it cold in the morning and adjust tire pressure accordingly. I do not worry about the change in psi during the travel day, as it does really change when you move into warmer or cooler temps.
  • Check tires before you leave and each morning before you go anywhere. That's what checking means in checking pressure cold. You could drive yourself nuts by overthinking the issue. could end up pulling over and making pressure adjustment after every turn in the road because of taking Sun from different direction.
  • I was talking to a fellow from the Highway Department in Montana a while back.

    In the winter, they store vehicles in heated garages because they are difficult to start when left outside.

    They have inflation tables to "over" inflate the tires in the heated garage because the tire pressure will go down when they get out in the cold, and they need to avoid under inflation.
  • rgatijnet1 wrote:
    The tires are designed to handle the variances in tire pressure caused by temperature.
    Look at it this way....suppose you are in a hot location and the outside temps is 100 degrees. You are carrying the maximum load so you inflate the tires to the sidewall max. Obviously once you hit the road, the tire temperature will increase, which will increase the tire pressure even more. Even tho this is above the max on the sidewall, it is not a problem and is still well within the tire design specs.
    As you know, under-inflation is what kills most tires.
    I agree with Ronny's post and under inflation does cause extreme heat build up!
  • Check and adjust cold pressure where you are. Cold is not driven and without sun exposure.

    If you have a drastic change altitude or temperature then recheck cold again the next morning.
  • In the spring I will adjust my tire pressure on a 80 degree day.

    I leave it that way even though I will sometimes be in 100+ degree situations.

    In the fall I'll set it on a 40 degree day.

    It will stay that way until spring. We'll be headed across the country to Florida this Jan/Feb/March and I'll leave the tire pressure alone.