Continental Tires PSI rising 20

[SGTJOE]

I recently bought Continental 255/70R 22.5's for my Tradewinds, it has always ran Michelins but none were available. I'm traveling from Southern Utah to Southern Arizona and am running 100psi in all 6 tires. I have a TST TPMS that I've used since TST first started that monitors each tires temperature and psi. The 100psi goes up to 120psi going down the road at 65mph. Outside Temps were running high 50's/60's. The Michelins never went up this much. I don't think they ever went more then 6-8 psi, even in 108 outside temperatures. My Honda CRV tow vehicle only gains 2 to 4 psi and these are with Continentals also. My old Michelins were 14 ply and the new Continentals are 16 ply, could this be the cause???

Is there anyone on here who is running the same size Continentals with a Tire Pressure Monitor System that monitors PSI and Tire Temps?? One more thing my Tire temperatures were running a few degrees above the outside temps. The tires were not hot at all, only problem is the 20 degree rise of the psi

[Lwiddis]

“before TPMS you never knew or even thought about how much they increased.“

I love new things to worry about! (Not)

[Chum_lee]

There are some well known "leak sealants/lubricants" which use relatively low boiling point hydrocarbons that can cause excessive pressure rise. Did the shop that installed the new tires by chance . . . . . install . . . . anything else, other than the new tires? IMO, a sniff test for contaminates inside the tires is in order.

Chum lee

[wolfe10]

rgatijnet1 wrote:
Tire pressure usually goes up when the temperature goes up.

Let's restate that:

Pressure WILL go up as temperature rises. Well proven in the 1800's. Still true today.

PV=nRT

https://en.wikipedia.org/wiki/Ideal_gas_law

[CapriRacer]

Second vote that the data points don't match: If the pressure goes up, so should the temperature.

While I like the idea of reinflating the tires with known dry air (or nitrogen), I'll bet that makes no difference - which would prove my contention that even with known water in a tire, it hardly affects the pressure buildup at all.

[SGTJOE]

Octaneforce wrote:
Do you notice any vibrations? Maybe these tires aren’t balanced as well and causing more heat.

There has been no vibration.

[Octaneforce]

Do you notice any vibrations? Maybe these tires aren’t balanced as well and causing more heat.

[rgatijnet1]

Tire pressure usually goes up when the temperature goes up.

[K_Charles]

MountainAir05 wrote:

rgatijnet1 wrote:
Sometimes when a tire is mounted by a rookie, he will use an excessive amount of lubricant to get the tire in place. All of that excess lubricant/moisture may be in your tire and causing your temps to increase a little higher than normal, since you did not have that issue with your other tires.

I am reading pressure went up not temp.

The OP said "20 degree rise of the psi" so is that degrees or pressure?

[MountainAir05]

rgatijnet1 wrote:
Sometimes when a tire is mounted by a rookie, he will use an excessive amount of lubricant to get the tire in place. All of that excess lubricant/moisture may be in your tire and causing your temps to increase a little higher than normal, since you did not have that issue with your other tires.

I am reading pressure went up not temp.

[rgatijnet1]

Sometimes when a tire is mounted by a rookie, he will use an excessive amount of lubricant to get the tire in place. All of that excess lubricant/moisture may be in your tire and causing your temps to increase a little higher than normal, since you did not have that issue with your other tires.

[Chum_lee]

"Water vapor causes some deviations from the ideal behavior as at typical tire temperatures and pressures water doesn't quite respond as an ideal gas. Maybe the air you have in the tires isn't particularly dry."

Just a guess. You might want to try bleeding the existing air from the tires and filling them again with . . . . KNOWN DRY AIR! Having filled the tires with excess humidity may be an issue. 20 psi change from cold to hot is a lot especially in winter time. I'm generally not a fan of using nitrogen in RV tires but that would be another option if dry air doesn't help.

Edit: Do all the tire pressures rise equally? Have you checked the tire pressure with a KNOWN GOOD MECHANICAL GAUGE to confirm that your TPMS is reading correctly and that the known good gauge and the TPMS are reading consistently? In aviation you really need not one, not two, but three independent ways to confirm the accuracy of your data to be confident.

Chum lee

[Sam_Spade]

SGTJOE wrote:
One more thing my Tire temperatures were running a few degrees above the outside temps. The tires were not hot at all, only problem is the 20 degree rise of the psi

Those two pieces of data don't match.

Have you actually felt the tires to see how hot they really ARE ?
HEAT is the only thing that will increase the pressure.

I think there is no validity to the temp readings of a TPMS.....since the sensor is not mounted on the tire itself. For tires your size, they often are at the end of a VERY long metal valve stem.

I don't pay much attention to the actual readings on my TPMS as they aren't very accurate but seems like I remember increases similar to that in the summer time. I have "off brand" truck tires.

[William_B]

Mine go up at least that much. What is the problem? They are designed to do it, and before TPMS you never knew or even thought about how much they increased.

[garym114]

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