Tire pressure before going south

[J_E]

I am curious what others do about air pressure in your fifth-wheel tires. If you set it at proper PSI in the north at 30 degrees and then end up in FL at 90 degrees, what effect will that have on the tire pressure?

[NC_Hauler]

Sam Spade wrote:

phillyg wrote:
Tire manufacturers compensate for temp changes. Always set pressure in the AM and don't change it until the next morning. They may fail for some reason but it won't be from failing to compensate for ambient temps.

While that is good general advice, one also needs to be aware of unusual conditions.

Some places in the western US it is easily possible to drive in a single day where you might have a temp. span of 70 degrees or more; high in the mountains down to death valley for instance.

Under extreme conditions like that you should check and correct the pressure more often.

Not according to the tire manufacturer. I wouldn't leave WVa in 18 degree weather, hit the Fla state line where the temps are pushing 80, pull over and let air out of my truck tires and 5er tires, (THAT ISN'T COLD AIR PRESSURE CHECK), .I'd wait the next morning and re-check cold air pressure and adjust accordingly. It's there for the research.

[NC_Hauler]

WAYYY over thinking a simple answer to OP's question. I'm OCD when it comes to checking tire pressures on all my vehicles as well as our 5er., but as stated earlier, just check the tire pressure the next morning.. You'll use the recommended tire pressure for your tow vehicle, just like you'll check tire pressure on your 5er and go by recommended psi for those tires as well, OR air to psi that you normally would when checking the tires COLD air pressure, i.e., after TV and 5er have sit over night. I've left one place where temps were in single digits..aired tires on truck and 5er to recommended cold air pressure, traveled to a location where temps got into the 50's and adjusted my truck accordingly the next morning and re-checked air pressure in the the 5er's tires the morning we left... It's really simple. Never had an issue with tires running over inflated, under inflated, worn out early, etc..

The tire manufacturer has figured all this in when Engineering and manufacturing the tires, and have set max sidewall cold air pressure accordingly.

[RAS43]

Do you believe that commercial drivers, who travel all over the country in all the conditions you describe, adjust air pressures? NO! As others here have described, check air pressures when tires are cold (morning) and travel on. I am in the west, go to altitude and back down all the time and do not adjust pressures. No reason to do that as today's tires are designed for various conditions.

[Sam_Spade]

phillyg wrote:
Tire manufacturers compensate for temp changes. Always set pressure in the AM and don't change it until the next morning. They may fail for some reason but it won't be from failing to compensate for ambient temps.

While that is good general advice, one also needs to be aware of unusual conditions.

Some places in the western US it is easily possible to drive in a single day where you might have a temp. span of 70 degrees or more; high in the mountains down to death valley for instance.

Under extreme conditions like that you should check and correct the pressure more often.

[Sam_Spade]

portliz wrote:
Is the pressure stamped on the tire the cold pressure?

It is the MAXIMUM cold pressure and should only be used when carrying the max. recommended load (although others will disagree).

[Calicajun]

My tires were inflated to 85 pounds rear and 80 pounds front in Huntington Beach, CA. We then drove to Klamath Falls, OR with its 2 degree temperature and the tire pressure dropped to 68 pounds because of the cold. So IMO you should always watch your tire pressure. Should also mention that my tires are filled with Nitrogen.

[jadatis]

The recomended pressure is for about 18degrC/65degr F to 20degrC/70degr F.

When ambiënt temp is lower the pressure is a bit lower too , wich gives more deflection so more heatproduction.
But then the cooling down is also more because of the moer temp difference between inside and outside tire. So you dont need to put higher presssure at lower temps.
The other way around when higher ambiënt temp , the cold pressure rises and so lesser deflection so lesser heatproduction, and because of lesser temp difference between in and outside tire the cooling down is also less .
to make it short , if you recalculate the pressure determined for 65 to 70 degrees for the ambiënt temp, the heatproduction and cooling down stays in line so no part of rubber of tire gets to hot.

For fuel saving its always better to keep the pressure higher also when cold, but then it will get to high when temp rises.

But an LT and Trucktire's maximum pressure on sidewall is not the maximum cold pressure but the presssure needed for the maximum load up to max speed of tire.
The maximum allowed cold pressure by the tiremakers system is 1.4 times this maxloadpressure/AT-pressure.
So if pressure rises above the AT-pressure given on sidewall cold, its not a problemm. Tires are tested to can stand a presssure of 2 to 3 times AT-pressure.

On Standard load and XL/reinforced/Extraload P-tires the maximum allowed cold pressure is given of between 44 and 51/ XL60 psi, and the AT-pressure is SL 35psi and XL// 41 psi in American system always.

This difference between AT and max pressure gives a lot of confusion , and AT-presssure is often called maxpress wich makes it more confusing.

[phillyg]

Tire manufacturers compensate for temp changes. Always set pressure in the AM and don't change it until the next morning. They may fail for some reason but it won't be from failing to compensate for ambient temps.

[portliz]

Is the pressure stamped on the tire the cold pressure?

[retispcsi]

I use a tire monitor system for my fifth wheel and my truck has one from the factory. I have traveled a lot this last spring, summer and fall. I have gone from 40 degrees temps to 117 degree temps. Mountain range in the east and west. Did 14K miles and 26 states this summer. I keep my tires at or very near max cold pressure regardless of the outside temps. My fiver has 125PSI tires and my truck 65 and 80 PSI rear. I monitor the pressure with my gauges while driving which is pressure and temp on the trailer. Your pressure will rise and the tires will heat up. If they are at or near max in cold weather they will not diminish when driving and they will heat up as you drive. Maintain the recommended cold pressure regardless of the outside temp and you will be fine. Check you pressure manually at least once a week with a good quality gauge. It is not uncommon for tires on aluminum rims to lose a few pounds of pressure over a month or so.

[Sam_Spade]

Coach-man wrote:
People worry about tire pressure with temp's and altitude?

Yes we do and maybe you should to.

The pressure changes with temperature and altitude and if the swing is wide enough the difference in pressure can make a significant difference in tire wear and safety.

Those simple facts have not changed over the years.

[golf_bears]

I leave home (WI) in late Nov. after setting the air pressure for the temps there. When I get in warmer climate, I will eventually adjust the pressure for that part of the country I'm in. If I don't reset my TPMS system alarm with keep beeping.

[Coach-man]

Unless you inflate your tires to the max in minus degree weather, should not be a problem! People worry about tire pressure with temp's and altitude? May have been a problem years ago, but today's tires should be fine! Set at proper cold temp pressure and drive on!

[midnightsadie]

X2

[Sam_Spade]

NHIrish wrote:

You need to check your tire pressures and adjust accordingly as you move from cold temps to hot temps...or the other way around,

It depends on where they are set to start with, in relation to the max. stamped on the sidewall.

Going from cold to hot, if the pressure at your morning check doesn't go above the recommended max. you can leave them alone until your destination.

Going from hot to cold, add about 4 LBS before you start out but not going over the max. That should get you well into your trip before you have to worry about adding more.