Tire pressure, question on increase.

Winged One wrote:
14,500 lb loaded trailer,

Around 11,200 on 4 tires (7,000 lb axles).

Goodyear G614 tires, about 3 years, 7000 miles on them.

Ambient temperature: 78 degrees. After running 1 hour on mixed highway (63 mph) and two lane (56 mph), trailer tires temp at 86 degrees.

Pressure increase from cold by around 12 percent. All tires within 1 degree of each other and within 2 psi of each other after 1 hour.

Normal?

Fairly normal from my experience.

Normal ??
It can be.
As others mentioned highway speed and the sun can create higher pressures and tire temps.
Also out here in the plains strong side winds can load the tires on one side and unload the tires on the other creating a big difference in a tires pressures and temps. Very noticeable in a all day run.

Max cold set sidewall pressures keeps a cooler running tire.

I have not put and used my TPMS on the trailer yet but have the EEZtire on the motorhome and Jeep toad. Tires typically will rise 10-15psi and temperatures will rise dependent on position and sun/surface temperatures. The Jeep right front tire gets the hottest of all the toad tires due to motorhome exhaust. While driving sunny side doesn't make much difference but parked it does. The motorhome doesn't have ST obviously and pressure for them is dependent on weight and position. Changes in temperature and pressure are rather consistent with them while driving.

Yes....normal! You may even see a small temperature and consequent pressure increase....After an extended drive on a road with significant crown. The tires on the “downhill” side will be somewhat more heavily loaded...and can show a small pressure increase over the other (uphill) side. One of those many anomalies in the RV world!

I run G Goodyears. Please note max air pressure is not the recommended tire pressure for your tire and rig. The G tire can handle up to 35,000 lb. loads. A 14,000 lb. 5th wheel is less than half. So, if max tire pressure is 110 lbs., then 80/85 for a 5th wheel seems reasonable. And if you do not want to change tires every couple of years I suggest running at 80/85. If you know a good tire guy ask um. Best way of knowing what's best for you, run at 80 on a trip and look at the tire each day. dust on the tread will tell you if you are wearing inside or outside or even. Adjust each day by 5 lbs. until you get even wear. No gratuity required. Happy travels.

My normal change in the summer is from 110psi to somewhere in the mid 120 range, with a split of 6 to 8 PSI difference between sun and shade side of trailer. Even with it just sitting there not moving I can get more than a 10percent increase from sunrise, to afternoon heat. My truck is the same.

If all four tires are close to the same I WOULD NOT WORRY ABOUT IT AT ALL.

Tires in the sun are always hotter than in the shade and that raises the PSI somewhat.

My 17,000lb trailer started out each day of travel with 115psi in the Goodyear H rated 4,805 lb max load capacity tires. When we moved we would normally cover approx 350 miles and the tire pressures would increas to 142psi to 146psi on all tires on the trailer. Seems those tires just liked to run at that pressure when warmed up. I tried to increase the cold temps by 5 psi and they still ran up to the 142 range. The temps reading was always above the out side temps by at least 25 degrees after a few hours of running. On two occasions the temp alarm sounded at 157 degrees and both times I had a stuck capliper on the truck causing the heat to radiate into the tire and wheel. I ran the TST systems on the rig and would always have faith in that system to let me know if and when somethng was out of whack.

RCMAN46 wrote:
When I am towing my 5th wheel the rear tires on my truck experience the greatest tire pressure change. They are also the tires loaded closest to the tire rating.

I have the TST system and have found the tire temperature totally useless.

My TST system does not even come close to that. Typically it indicates about 10 to 15 degrees F above ambient.

The TST does not have any air exchange with the tire and is being cooled by a 60 mph ambient wind.

^^^^^Same here better to use a digital thermometer. Watch for equal and consistent temps on all tires.

CapriRacer wrote:
Rule of Thumb:

There should be no more than a 10 percent increase in pressure.

Since you've got 12 percent, that's just a bit too much. You should seriously consider using more inflation pressure - or a larger size tire - somehow raise the load carrying capacity. Or you could slow down.

Please note: 10 percent is not a target. It is a max.

The 215/75R17.5 Goodyear G114 Unisteel fitted under heavy 5th wheels such as our 19000 lb GVWR Mobile Suites is rated 4805 lbs @ 125 PSIG. It routinely runs at 142 to 145 PSIG after a few hours on the Interstate at 65 MPH. That pressure increase is not just my experience - it's been confirmed by a number of other individuals using this tire here on this forum. Pulling off the Interstate into a rest stop, I can still lay my hand comfortably on the tread.

Rusty