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

NO, the temperature increase you are seeing is perfectly normal. Your Michelins did the same you just don't remember. All motorhome tires will build air pressure as they run down the road some a little more than others due to tread resistance and side wall construction.

quick way to see if they in deed go that high is check cold and once they are hot, pull over and check them manual. My only go up 4 max but not your brand. They are Michelin.

WOW, 20 psi gain seems too much to me at those low temperatures! I don't have an answer to your problem but good luck figuring it out! I would definitely check the tires with a reliable gauge and if the readings are correct I would call the tire company for support!

Pressure increase is directly related to the air temperature (and the outside air pressure); it's a simple matter of physics and has nothing to do with the brand of tire. Assuming basically dry air, it very nearly obeys the ideal gas law. 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.If you've driven up a mountain, the increase in altitude will cause a small increase in measured tire pressure since the atmospheric pressure goes down a bit. It's not a huge difference, less than 5 psi for any road you're likely to encounter.

Continental Tires PSI rising 20 | Good Sam Community

Lwiddis
Explorer II
Dec 11, 2019
“before TPMS you never knew or even thought about how much they increased.“

I love new things to worry about! (Not)
Chum_lee
Explorer
Dec 09, 2019
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
Explorer
Dec 08, 2019
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
Explorer II
Dec 08, 2019
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
Explorer II
Dec 08, 2019
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
Explorer
Dec 08, 2019
Do you notice any vibrations? Maybe these tires aren’t balanced as well and causing more heat.
rgatijnet1
Explorer III
Dec 07, 2019
Tire pressure usually goes up when the temperature goes up.
K_Charles
Explorer
Dec 07, 2019
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
Explorer II
Dec 07, 2019
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
Explorer III
Dec 07, 2019
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.