Adjusting Tire Pressure

[ArkRVHog]

So from going from the hot south to the cooler north, I've had to add about 5#'s of pressure in my Class C tires to get them up to specs. It has continued to cool a bit so checking my TPMS, I'm down about another 3-4#'s but once I'm on the road for 30-45 minutes...all tires are above inflation specs as normal.

Is this anything I really need to worry about this time of year? Thx.

[nvs4602]

For correct load tire pressure is at the cold tire temperature.

I would say the majority of people would not know or realize what you are seeing on your tpms. They would simply check pressure before the left and drove home.

A tpms for some is probably to much information and makes the fret over the slightest changes. If you have weighed your rig and know all 4 corners weight and determined you can run at say 115psi vs 120psi by the weight chart for your tires vs the plaque on the door. This is to me more of a debate, do you run at the lowest pressure and worry about what you are seeing? Or run at the recommended pressure and know you can drop 5psi and still be good.

I don't like to have to fiddle with tire pressure all the time so I would go rated pressure and have the safety cushion vs running at the minimum pressure to meet weight, knowing that I now have no margin for error.

[Jim34RL]

When I was towing my 5er (I am permanently parked now) I would adjust my tire pressure in the AM before leaving the campsite for that day's travel. I always adjust the tire pressure to the recommend cold maximum inflation air pressure, for me that was 110PSI. I would also check lug nut torques values when I check the air pressure. I would also rub my hands over the inside of the tire trying to feel for bulges.

[pgandw]

Originally Posted by ArkRVHog

So from going from the hot south to the cooler north, I've had to add about 5#'s of pressure in my Class C tires to get them up to specs. It has continued to cool a bit so checking my TPMS, I'm down about another 3-4#'s but once I'm on the road for 30-45 minutes...all tires are above inflation specs as normal.

Yes, tire pressures decrease when the weather gets cooler. You should be adding air when tires are below the correct pressure as measured in the morning. Under-inflated tires will heat up more than fully inflated tires when rolling, making rolling measurements a crap shoot. Every year, in Colorado, a cool fall night will result in a bunch of TPMS warnings the next day, and the tire shops will be full. My first check was to see if all 4 tires were reading slightly low. If yes, I needed to add cold winter air to the tires. If one tire was low, I had a tire problem.

Tire pressure also decreases when you go to significantly lower altitudes.

When I lived in Colorado, I would adjust my starting cold tire pressures a couple of PSI higher if I were going to a lower altitude, and add a couple of PSI more if the predicted weather was going to be cooler. That way, I would not be under-inflated in any likely conditions. I also have about a 10PSI margin according to the tire weight capacity charts by using the camper placard/tire sidewall pressure (same on my camper).

I am running OE Castle Rocks on their 4th year on my camper with no issues. I think a part of that is from not overloading or under-inflating.

Fred W
2019 Flagstaff T21TBHW A-frame
2022 Hyundai Palisade

[Aussieguy]

only check the actual pressure before you set off on a days driving. Adjust if needed



while driving you can use the monitor to make sure that you don't have a leak.
don't be worried about a very small difference in pressure between each tire



only worry about if a tire shows decreasing pressure... from when you started driving