Tire pressure before going south

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.

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.

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

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.

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.

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.

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.

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.

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,

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