Maximum hot tire pressure?

[wanderlust99]

I set tire pressure to 80psi cold per recommendations. (We're close to maxing out weight on both axles, class C 32ft). The real-time TPMS has the opportunity to set an alert at high ( as well as low) pressure. Pressures run hot in the high 90's after 80 psi cold. Is there a max hot pressure I should be worried about?

[EA37TS]

Originally Posted by wanderlust99

I set tire pressure to 80psi cold per recommendations. (We're close to maxing out weight on both axles, class C 32ft). The real-time TPMS has the opportunity to set an alert at high ( as well as low) pressure. Pressures run hot in the high 90's after 80 psi cold. Is there a max hot pressure I should be worried about?

That question should be directed to the tire manufacturer.

[16ACE27]

Originally Posted by wanderlust99

I set tire pressure to 80psi cold per recommendations. (We're close to maxing out weight on both axles, class C 32ft). The real-time TPMS has the opportunity to set an alert at high ( as well as low) pressure. Pressures run hot in the high 90's after 80 psi cold. Is there a max hot pressure I should be worried about?

I don't have your tires but my 82 PSI cold tires can easily top 100 PSI in the summer on hot days on my 16K F-53 chassis. I set my high alarm at 105 PSI.

[Pete'sMH]

I wouldn’t worry about it. Just set your cold pressures and let them do what they do.

[Lt Keefer]

Nope, set the pressures cold and enjoy the coach. There are too many things to worry about on an RV to worry about any of them.

[Elite Washington]

We have a 32ft class c as well, our rears will get from 92-97 outside versus inside during the summer. Watching your speed helps a lot as well. Going to be a lot higher running 70mph in the heat of summer versus going 60-65.

[lwmcguire]

You will get different temperatures from each tire manufacturer and from most fellow owners.

Good advice already, and mine is to watch the inner dual. Usually, the hottest as it doesn’t cool as well, and if your exhaust is close to one side, you might watch that one closely.

I check mine when stopping each time as a habit for many years.

If you're constantly running hot or getting significant psig increases above your comfort zone, then heavier rated tires next time

[Jimbo56]

Originally Posted by 16ACE27

I don't have your tires but my 82 PSI cold tires can easily top 100 PSI in the summer on hot days on my 16K F-53 chassis. I set my high alarm at 105 PSI.

I do same.

[EA37TS]

Originally Posted by 16ACE27

I don't have your tires but my 82 PSI cold tires can easily top 100 PSI in the summer on hot days on my 16K F-53 chassis. I set my high alarm at 105 PSI.

Tire Minder sets the high pressure alarm at 20 percent higher than the cold temperature tire pressure setting. Since my cold pressure is set based on actual CAT Scale vehicle weight (100 PSI) it is lower than the manufacturer’s sticker weight (110 PSI). Traveling during 100 degrees days we rarely saw an increase of more than 7 PSI in any tire. Usually the inner duals will increase by 2 PSI over the outers.

[wanderlust99]

Thank you everyone for the replies, very helpful. I've set the max alarm to 120psi which is 50% higher than cold temp, as suggested by rvtiresafety.net, the fellow seems to be a reliable source. As I recall the max I saw was about 105psi in 80 degree heat (80psi cold was set at about 40 degree ambient). Thanks again!

[santos1060]

Thank you for all these insights, I've just traded my Class C for a Class A and I'm having to start all over again on knowledge like this. Curious to hear what your experiences have been on high/low tire pressures and when you'd be worried. So if 80psi is cold and the temp drops while you're on a trip, have you seen it get below 70? Conversely, if you start up north, travel south into 90+ deg temps, at what tire pressure level (i.e. 110psi) should I start thinking about letting some air out? In my Class C I knew if it got below 60psi I was going to have problems if I didn't add, and if it got above 90psi that would have been quite rare and caused me to let some air out. Thanks in advance!

[Hooligan2]

It's not that precise. Tire pressure changes by 1 psi for each 10 degrees temperature change. If you check your tire at 90 degrees that morning and that afternoon it is 30 degs, you have only lost 6psi... Check your pressure when cold each day. Do not let air out of hot tires to meet chart pressure.

Technically tire temps are based on 68 deg f.

[RV Driver]

My 110 psi steer tires will go to 126 psi after a few hours on the interstate on an 80+ degree day. I never give it a moments thought.

[16ACE27]

Originally Posted by santos1060

Thank you for all these insights, I've just traded my Class C for a Class A and I'm having to start all over again on knowledge like this. Curious to hear what your experiences have been on high/low tire pressures and when you'd be worried. So if 80psi is cold and the temp drops while you're on a trip, have you seen it get below 70? Conversely, if you start up north, travel south into 90+ deg temps, at what tire pressure level (i.e. 110psi) should I start thinking about letting some air out? In my Class C I knew if it got below 60psi I was going to have problems if I didn't add, and if it got above 90psi that would have been quite rare and caused me to let some air out. Thanks in advance!

I've never seen a "cold measured" tire pressure go down while driving. The tires always heat up.,

[Chateau_Nomad]

Originally Posted by 16ACE27

I've never seen a "cold measured" tire pressure go down while driving. The tires always heat up.,

I'm guessing the OP is referring to tires that have sat overnight to cool? But 10psi ?? That sounds pretty extreme like something else is going on.

[CHS]

According to TST TPMS they say to set the alarm settings for High pressure at 20% above cold pressure and the low to 10% below the cold pressure.
For High pressure 80 PSI = 96 psi
For Low pressure 80 PSI = 72 psi
If your within the GVWR, I would set it and forget it.

https://www.youtube.com/embed/tykU-sg96S0

[CactusJuice]

Set them high enough that you don't get nuisance alarms - probably around cold inflation +20-25%. What is more important to watch is the relative temperature change. If they are all 20 lbs high, then don't worry about it. If one of them is high and the rest not, then it's time to investigate.

[RACarvalho]

Originally Posted by wanderlust99

... Is there a max hot pressure I should be worried about?

Max cold tire pressure on our tires is 95PSI.
I always set them at 90PSI and during summer it usually reach 114PSI on highway but once it reached 117PSI and the alarm for over pressure, as I set it, went off...Never had a problem with tires...

[Judge]

There is another factor in play in this discussion.......

The amount of moisture (humidity) you put in your tires if you used compressed air and not nitrogen can impact the increase in tire pressure and temperature and the tires heat up under use.

If you don't use a drier on the compressor line filling the tires you will put a lot more moisture into your tires if you are filling them in Florida vs Arizona in August. Moisture in the tires causes greater pressure fluctuations due to temperature and that also impacts the tire temperature itself.

[lwmcguire]

Originally Posted by CactusJuice

Set them high enough that you don't get nuisance alarms - probably around cold inflation +20-25%. What is more important to watch is the relative temperature change. If they are all 20 lbs high, then don't worry about it. If one of them is high and the rest not, then it's time to investigate.

Best advice you can possibly get!