Tire inflation vs altitude vs load distribution

[P & T]

I asked this question on another thread but I now have some extra TH related questions:

"Where is the best place to get trailer tire inflation "best practices "?

I've been watching my TPMS and have been adding air (and bleeding air) frequently to maintain the 110 psi on the sticker. Always when the tires are cold but how much should I worry about the sunny side vs. the shady side. Ambient is ambient.

Yellowstone park this morning was about 50 deg F ambient at 8am. My shady side was about 103 psi cold-average. Sunny side was 108 psi cold-average. I pumped up everything to 110 psi. Got to Idaho and dropped about 1500 feet in elevation. Now my shady side (from the morning that was ~103 psi) was 115 psi cold-average and the other side was at 108 psi cold-average. Is my "shady side from the morning" over inflated? I bled the air to match the 108 psi and will recheck in the morning.

Sailun 235/80 R16G tires. I use a handheld digital gauge to compare to the TPMS. This is going to drive me batty and I'm probably overthinking things. Thanks in advance."

This morning at 58 deg F ambient (and no sun on any tires), my TPMS is reading 100-102 psi and 48-50 deg F.

Is this where I should leave it alone?
Yesterday my shady driver side is what I inflated but going down the road those tires were running 8-10 psi higher than the passenger side, which is what prompted me to bleed off last night. Driver side was about 128 psi going down the road while the passenger side was 120 psi-ish.

I'm 1500 feet lower today. Is it good practice to adjust to the stickered 110 psi every 1000 '? 2000'? 4000'?

I need a full water tank for today so all of these readings are with the fresh tank full while grays and blacks are empty. My loads are distributed in the TH but do I consider any additional compensations on air pressure when I put a 1600lb toy in the garage? I see a lot of previous posts and tire charts on 2 axle conversations but not 3 axle.

I'll start with these questions and thanks in advance!

[wiredgeorge]

It is hard to imagine pulling a camper day after day and adjusting tire pressure day to day if the tires are not leaking air. Adjust cold on day one and then leave them be. I use max pressure as noted on the tire sidewall as I run LRE vs the original LRD. 80PSI. It would drive me nuts worrying about things like altitude and temp adjustment.

[bsmith0404]

Personally, I think you’re really overthinking things. If I understand correctly, you have a triple axle so 6 LRG feet on the ground. My guess is they’re rated somewhere around 4000 lbs each. That gives you 24,000 capacity. Even if you’re loaded to 20k, about 4k of that is on the pin so about 16k on the tires. That’s 8k of reserve So over 1,300 lbs per tire. I wouldn’t worry about a few psi. I’d set them for the altitude and temp at home and wouldn’t worry about small adjustments (5-10 psi) unless the cold temp was over 110. We just got back from a 30 day trip where we started out at 3k feet and 80 cold temps and spent a lot of time in SD and WY so 7k feet and 50 degree cold temps. I adjusted the air pressure before we left home on the final day of our trip before heading home. I don’t run the tires at 110, not enough weight on them and I was getting excessive center wear when I did. I run them at 95 cold so I’m not that concerned about how much they heat up when I go from cold to hot temps. I have over 1000 lbs extra capacity per tire as well, so not concerned about a few psi lost at altitude and colder temps.

[CWtheMan]

NHTSA says cold inflation pressures can be obtained after the vehicle has remained stationary for at least three hours.

[travelin texans]

As George said check them in the morning before traveling, that's the "cold" pressure, inflate to either the rv manufacturer recommended pressures posted on the tag or if upgraded to a larger size use the sidewall pressures. Pickup your self up a good digital pressure gauge set pressuresusing it & don't try to get the TPMS & gauge to ever match, close is good enough, or you'll drive yourself nuts.
If the pressures rise during travel, elevation or change in temperature, DO NOT let air out, they are designed to handle the increases in pressure & temperature, inflate "cold" wherever you at & leave them alone, check them again in a week, a month, or after you've stored it awhile, NOT daily or every time you stop.
Don't worry yourself sick over this!
I'd be more concerned with the brand of tires? If they're Trailer Kings or HiSpec or some other known "China Bombs" I'd be replacing them today if not sooner. It doesn't matter about the inflations on those few brands they'll blow up on the spare rack never haven been on the ground.

[CedarCreekWoody]

You are way over thinking this. Early one morning set the pressure to the recommended rate and watch you TPMS, only adjusting if the pressure drops below the recommended rate.

[Camp CA]

P & T.........Never adjusted tire pressure for loaded weight, altitude or ambient temperature in 18 years of towing fifth wheel trailersat ahigh altitude and cold/hot temperatures. The G rated tires are inflated to 110 psig maximum cold.

[gearhead]

Set the pressure before you leave home. Watch your TPMS. Sleep soundly.

[P & T]

Originally Posted by wiredgeorge

It is hard to imagine pulling a camper day after day and adjusting tire pressure day to day if the tires are not leaking air. Adjust cold on day one and then leave them be. I use max pressure as noted on the tire sidewall as I run LRE vs the original LRD. 80PSI. It would drive me nuts worrying about things like altitude and temp adjustment.

It's not so much that I worry, it's more like I want to know what my safe limits are and get dialed. I like to be proactive. Thanks.

[P & T]

Originally Posted by bsmith0404

Personally, I think you’re really overthinking things. If I understand correctly, you have a triple axle so 6 LRG feet on the ground. My guess is they’re rated somewhere around 4000 lbs each. That gives you 24,000 capacity. Even if you’re loaded to 20k, about 4k of that is on the pin so about 16k on the tires. That’s 8k of reserve So over 1,300 lbs per tire. I wouldn’t worry about a few psi. I’d set them for the altitude and temp at home and wouldn’t worry about small adjustments (5-10 psi) unless the cold temp was over 110. We just got back from a 30 day trip where we started out at 3k feet and 80 cold temps and spent a lot of time in SD and WY so 7k feet and 50 degree cold temps. I adjusted the air pressure before we left home on the final day of our trip before heading home. I don’t run the tires at 110, not enough weight on them and I was getting excessive center wear when I did. I run them at 95 cold so I’m not that concerned about how much they heat up when I go from cold to hot temps. I have over 1000 lbs extra capacity per tire as well, so not concerned about a few psi lost at altitude and colder temps.

I am definitely overthinking things, no doubt. But I want to know.

What are the low limits of inflation? At what point am I out of my reserve and in a danger zone. All things being equal, I am running Sailun S637 235/80 R16G's. From what I've read, these are good tires (everything from China is a bomb, I suppose) but Michelen, Firestone and Goodyear don't make this tire?

[P & T]

I hit the road this morning and tires got up to 117-118 psi. As the day warmed up and I pulled into the next site, it was more like 119-222 psi...I felt good about things.

Now load distribution is where I want to focus. I had a full fresh tank and empty everywhere else. My fresh will be about 50% and all the other tanks will be empty by the time I hit the road tomorrow. Is it one fresh tank or smaller tanks linked together that add up to 94 gallons? I'm guessing the it's smaller tanks and that helps distribute the water weight?

At some point, I'll be curious about what the 1600 pound UTV will do to pressures (one tire to the next).

[JRTJH]

Originally Posted by P & T

I hit the road this morning and tires got up to 117-118 psi. As the day warmed up and I pulled into the next site, it was more like 119-222 psi...I felt good about things.

Now load distribution is where I want to focus. I had a full fresh tank and empty everywhere else. My fresh will be about 50% and all the other tanks will be empty by the time I hit the road tomorrow. Is it one fresh tank or smaller tanks linked together that add up to 94 gallons? I'm guessing the it's smaller tanks and that helps distribute the water weight?

At some point, I'll be curious about what the 1600 pound UTV will do to pressures (one tire to the next).

Hopefully the part in red was a "typo"... If you were reading 222 PSI, then you were WAAAAAYYY over maximum pressure !!!!! Now, if it was intended to be 119-122 PSI, then I'd say "You're golden".... But, if it wasn't a typo, you've got some serious issues with that hub/brake on the wheel showing 222 PSI.....

[P & T]

Originally Posted by JRTJH

Hopefully the part in red was a "typo"... If you were reading 222 PSI, then you were WAAAAAYYY over maximum pressure !!!!! Now, if it was intended to be 119-122 PSI, then I'd say "You're golden".... But, if it wasn't a typo, you've got some serious issues with that hub/brake on the wheel showing 222 PSI.....

LOL, yes it was a typo. 119-122 psi is what I saw.

[bsmith0404]

As for your tank size question, yes multiple smaller tanks. For the most part the largest tank you’ll see in and RV is around 45-50 gallons, 43 seems to be the manic number. Frames have cross bracing in them and the tanks have to be sized to fit between the frame rails and the bracing. So yes, multiple tanks helps distribute weight more evenly across the chassis.

[P & T]

Originally Posted by bsmith0404

As for your tank size question, yes multiple smaller tanks. For the most part the largest tank you’ll see in and RV is around 45-50 gallons, 43 seems to be the manic number. Frames have cross bracing in them and the tanks have to be sized to fit between the frame rails and the bracing. So yes, multiple tanks helps distribute weight more evenly across the chassis.

That makes sense, thank you.

Tires were all at 105-106 psi this morning and got up to 128 psi by the afternoon rolling into 102 degree Vegas weather. The passenger front (I call it tire #2) was slightly higher than the other 5 but we were driving with a full fresh tank which is right over/in front of that axle. I'll have an empty-ish tank for the final return trip home and I want to see if that tires "unloads".

Only problem in Vegas so far is two of the 3 AC's keep tripping the breakers but the RV Park has crappy power. Good thing our daughters house has good AC.

[wiredgeorge]

Originally Posted by P & T

That makes sense, thank you.

Tires were all at 105-106 psi this morning and got up to 128 psi by the afternoon rolling into 102 degree Vegas weather. The passenger front (I call it tire #2) was slightly higher than the other 5 but we were driving with a full fresh tank which is right over/in front of that axle. I'll have an empty-ish tank for the final return trip home and I want to see if that tires "unloads".

Only problem in Vegas so far is two of the 3 AC's keep tripping the breakers but the RV Park has crappy power. Good thing our daughters house has good AC.

It appears you don't have an Electrical Management System (EMS) which will prevent damage from a park with a poor electrical system. The components that get fried are more expensive than a quality EMS. A surge protector is more or less a waste of money.

[P & T]

Originally Posted by wiredgeorge

It appears you don't have an Electrical Management System (EMS) which will prevent damage from a park with a poor electrical system. The components that get fried are more expensive than a quality EMS. A surge protector is more or less a waste of money.

Can you recommend an EMS? This is what I'm using, without the remote display.
https://technorv.com/products/50a-su...51?Click=11742

[gearhead]

You may also look at Progressive EMS. Great warranty.
Progressive industries.net

[wiredgeorge]

Originally Posted by P & T

Can you recommend an EMS? This is what I'm using, without the remote display.
https://technorv.com/products/50a-su...51?Click=11742

The Southwire 34951 should work fine and am surprised it did not shut down that RV parks poor power and you kept tripping breakers. I use a Progressive Industries 30A EMS: https://www.progressiveindustries.net/ems-pt-x

I am not electrical savvy enough to know why your Southwire EMS didn't catch the power issues that were tripping your breakers. Perhaps a smarter person could chime in.

[sourdough]

Your Surge Guard is a good unit, I have the same unit without the remote monitor. It has saved my bacon many times. If you're throwing the breakers inside the RV the Surge Guard won't help you if an individual RV circuit is overloaded. Each side of the EMS will carry 50A and your individual circuits in the RV will be 15 and 20A. If the park power is crappy and falls outside acceptable limits the EMS will shut down. If you're overloading individual circuits, which it sounds like, you need to see what is running inside when it trips the breaker(s). If trying to run 3 A/Cs at once 2 will be on one leg and that's probably what's doing it.