# Max Hot PSI for Tires.



## modalita (May 25, 2013)

So I'm set my tires to 40 PSI Cold in the morning. However, we have some variations in temperature, and when we get a swing of 30 degrees hotter during midday and I get the tires hot, they can run as high as 46 PSI. That said...what is considered the limits of safe PSI on tires when they are hot? I thought it was 44, but wanted to ask the community.


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## Dragonsys (May 27, 2013)

What does the max rating show on the tires? If it is 44psi, then 46psi should be ok, as long as it is not for extended periods of time. Are you verifying 46psi using a gauge, or just going off what the DIC shows?


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## obermd (Mar 3, 2012)

The max sidewall pressure is "cold" Unless there is a mounting error or damage to the tire, they can safely run a lot higher than that.


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## XtremeRevolution (Jan 19, 2012)

obermd said:


> The max sidewall pressure is "cold" Unless there is a mounting error or damage to the tire, they can safely run a lot higher than that.


To add to this, cold is defined as the coolest part of the day for a given season, after the car has been sitting for a while.

Tire manufacturers have built in a massive safety margin here in their sidewall spec. A tire won't actually burst due to pressure until you're above 200PSI. My Eco tires are rated for 51psi and I fill them to 50 just because I like even numbers and it's easier to read on a gauge. During hot days, my pressure climbs to 52-53psi, and that's perfectly safe.

Tire manufacturers knew that someone could potentially fill their tires to max sidewall during the winter in Illinois at 20 degrees and take a road trip to Texas and hit 80 degree temps, which alone would account for a good 6psi and an additional 2-3 as the tires heat up from friction on the highway. There would be endless lawsuits if such a huge safety margin wasn't factored into the tire specs.

Sent from AutoGuide.com App


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## modalita (May 25, 2013)

Dragonsys said:


> What does the max rating show on the tires? If it is 44psi, then 46psi should be ok, as long as it is not for extended periods of time. Are you verifying 46psi using a gauge, or just going off what the DIC shows?


 I filled to 40 using my gauge at 80 degrees outdoors. The new numbers are via watching the DIC. We are pushing 103 here in lovely TX today, which bumps my starting PSI up to 42-43 or so.


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## Dragonsys (May 27, 2013)

yeah, we are right around 100 here in Atlanta as well. The DIC is not always exact, so if you are worried about the numbers I would do a manual check as well. I did not know the max pressure on the side of the tire was cold, interesting, I always thought it was hot. Thanks for the info!


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