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?

[Mont_G_J]

From Tire Rack;
The rule of thumb is for every 10° Fahrenheit change in air temperature, tire pressures will change about 2% (up with higher temperatures and down with lower). This means that light-duty, standard-pressure tires (typically inflated to 30-50 psi) used in applications on cars, vans and light trucks will change by about 1 psi; where heavy-duty, high-pressure tires (typically inflated to 80-100 psi) used in applications on recreational vehicles, busses and trucks will change by about 2 psi.

[rdemore]

I just returned from Christmas in Cocoa Beach. We left Tn with the tires at about 78 psi cold. I have TPMS on the trailer, and by the the time we got to Atlanta the pressure was around 85-86 psi. Just south of Atlanta, we had a blowout, and the next morning a 2nd blowout. Replaced the two tires with Goodyear Marathons (only option on Sunday morning) and they set the pressure to 70 psi and suggested I look at the camper recommendation. I found it on the name plate and it was 65 psi.

Well, with all that said, two blowouts in 200 miles, no spare for the 2nd, I am curious about what happened and if air pressure had a effect. The two tires that blew were put on summer 2012.

[NC_Hauler]

avvidclif1 wrote:

NC Hauler wrote:

RAS43 wrote:
Well then I must be "asking for trouble", whatever that must be. I have been pulling trailers since '75 and never had any wear issues and only blew one tire, a Goodyear Marathon. And I do have a TPMS which has not indicated any issue. :C

Well then you're ok, though some refined calibration equip has found some TPMS off by as much as 10% at times...I use a high dollar digital read out that I can also have calibrated, so feel pt=retty good about it,

Look up the spec's on that gauge and let us know the percentage of error. Might be interesting.

It's a commercial digital read out for tires that I can check it's calibration with some pretty sophisticated calibration equipment that I can use ...It's within +/- 2 psi to actual reading.

[laknox]

J&E wrote:
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?

Check the tires every travel day and adjust, up or down, as needed. Tires are designed to warm up and carry a higher-than-cold pressure.

Lyle

[neal10a]

Why not follow the tire manufactures recommendations. When they say cold temperature they mean at 70deg F ambient with the tire at ambient temperature. The tire temperature will be above ambient while running. So one must let the tires cool before checking the pressure. My 110 psi tires get 50 deg F above ambient while traveling at highway speeds--and the pressure will be above 120 psi until they cool down to ambient. So it would be stupid to let air out of the tire when they are hot. When the tires are at 40 deg F they are below 100psi and it would be stupid to add more air at that temperature because they would be 110 psi when they get to 70 deg F.

[FlatBroke]

There are a gazillion tires on the road with varying application, if traveling from cold to warm was a big concern the highways would be littered with blown tires and wrecked vehicles. Then there would be a real climate change topic. LOL.
PS nice chart.

[jadatis]

Made a list of pressure chanches for temperature for at sea level so 1013 mb pressure outside the tire wich is 14.692 psi.

Used the most used advice pressures and AT-pressures of most loadranges tires.
Only goes for when inside tire is completely dry so no water in it. this is never the case but cold measurements dont give that much extra rising or dropping of pressure by the water in it.
At boiling point of water the water inside tire can maximally rise the pressure by about 14.5 psi extra above what is calculated in the list. From 65 to 100 degr F the extra rising of pressure by the water is max 0.65 psi if there is enaugh liquid water in tire to go over to gas.

Then you see for instance that 1 psi /10 degr F only goes for about 38 psi filled at 65 degr F wich I stated as the advices been calculated for ( some say 68 or 70 ). For for instance 80 psi the rising is between 45 and 110 degr F about 1.8 psi/10degr F.

In Holland where I live we use , and . the other way around as in America. so , instead of . before the decimals.

[jadatis]

Mind there are 2 reasons for tirepressure advice.
1 is for handling, traction and durability and fuel-saving.
2 is for savety of tire so it wont get overheated and damaged by that .

For reason 1 you should keep the cold pressure at the adviced or calculated pressure at the ambiënt temperature.
So then compensate for pressure dropping or rising by temperature dropping or rising. then use the rules of tumb , but I also made a spreadsheet for it.
The rule of tumb only goes for tires filled up to 45 psi , if its filled to 80 psi it will rise or dropp more. Better then would be to go from a sertain percentage of the cold filled pressure .

For savety of the tire the story is different, and I already explained that in my first reaction in this topic.
But in short , heating up and cooling down of tire takes care that no spot of the rubber reaches a sertain temperature that it hardens and crackes in next bendings.
When Ambiënt temp is lower more temp difference in and outside so cooling down is more so heating up can also be a bit more.
So the lower pressure so more deflection gives a bit more heatproduction but also better cooling down because of more temp-difference between in and outside tire.

so for reason 2 you dont have to fill up to calculated or adviced pressure when temp drops.

If you take care to have enaugh reserve in the pressure dont worry about ambiënt temperature dropping or rising and the pressure dropping or rising that goes with it.

Simple defenition of cold pressure is when inside tire temperature = outside tire temperature.
And thats not the case for instance when sun on the black tire.

[avvidclif1]

NC Hauler wrote:

RAS43 wrote:
Well then I must be "asking for trouble", whatever that must be. I have been pulling trailers since '75 and never had any wear issues and only blew one tire, a Goodyear Marathon. And I do have a TPMS which has not indicated any issue. :C

Well then you're ok, though some refined calibration equip has found some TPMS off by as much as 10% at times...I use a high dollar digital read out that I can also have calibrated, so feel pt=retty good about it,

Look up the spec's on that gauge and let us know the percentage of error. Might be interesting.

[NC_Hauler]

RAS43 wrote:
Well then I must be "asking for trouble", whatever that must be. I have been pulling trailers since '75 and never had any wear issues and only blew one tire, a Goodyear Marathon. And I do have a TPMS which has not indicated any issue. :C

Well then you're ok, though some refined calibration equip has found some TPMS off by as much as 10% at times...I use a high dollar digital read out that I can also have calibrated, so feel pt=retty good about it,

[RAS43]

Well then I must be "asking for trouble", whatever that must be. I have been pulling trailers since '75 and never had any wear issues and only blew one tire, a Goodyear Marathon. And I do have a TPMS which has not indicated any issue. :C

[Bowti]

When I leave Wisconsin it can sometimes be below 0 degrees out. I air up my tires to recommended cold pressure when cold. Each morning I will need to let air out as I hit higher temps, or my alarm will drive me nuts. Once at my destination I again set my cold pressures to the recommended cold settings.

For those that do not adjust your tires and ignore your alarms if you have them, when traveling from such different climates, I think you are asking for trouble.

[NC_Hauler]

Sam Spade wrote:

NC Hauler wrote:

Not according to the tire manufacturer.

Nowhere in my post did I say to be letting air out of your tires when they are HOT.

Going from a hot environment to a COLD one, however, can leave your tires dangerously low in some circumstances. If you will be driving very far after it gets cold, you should check them.

Remember the Firestone tires and Ford Explorers ???

How can you leave tire pressures dangerously low IF you check air pressure when tires are cold, before you start your trip?:h

And yes... I remember the Firestone tire and Ford Expedition fiasco, :R...really has nothing to do with this thread..

...and I have no idea now what you are talking about. I said check your tire pressure with tires cold before taking the trip, then, whether drastic temp changes or not, check them again the next morning when tires are cold ..have said that since the beginning.

Below is a snippet I copied on this topic.

"Tire inflation pressure and temperature
As discussed in some of our other articles on inflation pressure, tires must be properly inflated to achieve maximum handling, traction, and durability as designed by the tire manufacturer. It is the air pressure that supports the weight of your vehicle, not the tire itself. Tire pressure should be monitored frequently for safe driving and optimal tire performance.

Tire pressure can change with fluctuations in temperature. So, how should you correctly monitor tire pressure as the outside temperature changes?

First, it's important to remember that gas expands when heated and contracts when the temperature declines. In North America, the daily temperatures rise and fall between day and night, as well as seasonally. As the days get shorter and colder during fall and winter, it's especially important to check your tire pressure.

Second, it's important to know that the recommended tire pressure for your vehicle (as specified in the owner's manual and the tire placard for the vehicle) are both based on cold inflation pressure. This means that the tire pressure should be checked in the morning before the tire has been run, before the ambient temperature rises during the day, and before the tire is exposed to direct sunlight.

A good estimate to use when comparing tire pressure to air temperature is for every 10 degrees F, tire pressure will adjust by 1 psi. For example, if the outside air temperature increases 10 degrees, the tire pressure will increase by 1 psi. Conversely, if the air temperature falls 10 degrees, the tire pressure will decrease by 1 psi.

In most parts of North America, the difference between average summer temperatures and average winter temperatures is about 50 degrees F. This means that your tires will fluctuate approximately 5 psi (assuming no other air loss) between the coldest and warmest times of the year. A drop of 5 psi during colder months will affect traction, handling, and durability. This is why it's important to remember to check your inflation pressure, especially during colder times of the year.

In most parts of North America, the average daily air temperature fluctuates by approximately 20 degrees F. Using our rule-of-thumb formula from above, this means that the inflation pressure can fluctuate by approximately 2 psi during the day. This fluctuation can be even more pronounced if the tire is subject to direct sunlight.

In addition to changes from sunlight, the tires temperature is also affected by driving. Tire pressures can increase by up to 5 psi in the first 20-30 minutes of driving, before finally stabilizing.

If you live in a cold climate and have a heated garage, the opposite problem can occur. As soon as you leave the confines of your heated garage and go out into the colder weather, your tires can lose inflation pressure. Again, for every 10 degrees F dropped, the tires will lose approximately 1 psi each.

In all three scenarios, the same problem arises, regardless if you check the air pressure when the tires are warm from driving, when there are ambient temperatures, or if the tires are in direct sunlight. If the inflation pressure is correct when a tire is warm, then it will likely be anywhere from 2-5 psi under-inflated when it is cold.

Bottom line -- you should always check your tire inflation pressure when your tires are cold, and inflate them to the recommended pressure at that time. "

It is what it is.

[Dave_H_M]

Well I just aired mine up to 80 out in the barn where the temp is 30.

i am heading to SC and then to FL and will be back 1 March. I don't even intend to check air pressure unless one of the tires seem to be bulging more than the rest.

Kick the tire and light the fire. :B

[Sam_Spade]

NC Hauler wrote:

Not according to the tire manufacturer.

Nowhere in my post did I say to be letting air out of your tires when they are HOT.

Going from a hot environment to a COLD one, however, can leave your tires dangerously low in some circumstances. If you will be driving very far after it gets cold, you should check them.

Remember the Firestone tires and Ford Explorers ???