Tire pressure

[rp53]

i know this will probably open a can of worms, Lets say for comparison your max tire pressure should be 50 lbs, if you air them up cold to 50 lbs it stands to reason when they get hot the will be over inflated. so do you air them to say 45 lbs. what do most of you do ?

[270S]

Unless you are having 50+ temperature daily swings, set correct pressure (many factors determine correct # - not necessarily max, usually manufacturer label is correct) when the tires are at ambient temperature in the am - cold. That straight forward.

[Ford Idaho]

Air them up to the sidewall stamped pressure when cool/cold and leave it that way.

Nothing is gained by running under inflated tires.

[270S]

Originally Posted by Ford Idaho

Air them up to the sidewall stamped pressure when cool/cold and leave it that way.

Nothing is gained by running under inflated tires.

A lot is wrong with overinflated tires too. Many factors determine proper tire pressure. The stamped sidewall pressure is when the tires are at max weight capacity, usually not the average load actually on them. My RV was set to 100 (seems typical thought process - WRONG) when the label (not tire sidewall) said 82. It rode like a ROCK on steel. I spent $$$$ until I discovered the wrong way overinflated tires.

[spock123]

I check the tires in the morning when the tires are cold. I set the tires on the truck at what the truck says, in my case 60psi in front and 80psi in rear. On camper it says to set the air in tires at 110psi and that's what I do. I have a TPMS, TST 507 and I watch the the psi in the tires go up. I also watch as the temperature go up in the tires as the air temperature goes up. Plus the tires get warmer riding on the road. I never think about letting air out just because the temperature goes up. I check my tire pressure once a week with a digital gauge, the rest of the week I trust my TPMS. If I am going from a cold part of the country to a warmer part then I check the tires with my digital gauge more often. First thing I do every morning is turn on the monitor on my TST and check the psi in each tire, I sometimes leave the monitor on overnight. If I see the psi is to much in the tires when they are cold then I adjust the pressure and vise versa if the tires don't have enough pressure. The best advice I can give you or anyone for that matter is to buy a TPMS that you trust. TPMS should come standard on trailers, it's the only way you have to know the psi and temperature on the tires riding down the road. If one of your trailer tires should go flat you will tear the tire up plus the side of your camper unless you are lucky and the person behind you tells you something is wrong with a tire. Anyway it works for me

[KFX450RXC]

The rise in temperature from heat is to expected. The manufacturers know that as well.

As has been mentioned, go to maximum pressure when cold and ride on. Your 50 psi may turn into something in the 60s but the tires should be fine.

[KingFisher]

I shoot for the 80 psi on the sidewall, I ended up getting 77.5. Even in 85 degree heat at 65 mph the tires only gained 10 pounds of pressure.

[doulos]

If they say 50psi cold, then that's what you should do. The tire manufacturer isn't ignorant about pressure increasing with heat... seriously, they know!

Now if you're going to drive over the recommended maximum speed for your tires then, all bets are off and good luck! [emoji51]

[jadatis]

The adviced pressure and also the pressure behind AT on the sidewall ( yours 50 psi) is always given with ( cold ) behind it.
And as already written here, the pressure rising by temperature rising by driving is taken into account .

In fact the Cold advice is for about 18/20 degr C/65/68 degr F.
And cold pressure is when inside tire temperature = outside tire temperature( ambiënt temp).

The goal of pressure advice is to give the tire a deflection that gives the tires rubber not at any spot a temperature at wich to many sulfur bridges form so it hardens, and crackes in next bendings of rubber by deflections.

Realise that every segment of the tire deflects and flexes back about 10 times a second when driving about 50m/h.

Every cycle a sertain heatproduction , more deflection> more heatproduction a cycle.
Higher speed means more cycles a second so more heatproduction a second.

So heatproduction a second = heatproduction a cycle X cycles a second.
cooling down of tire is dependent on temperature differences, and not on speed.

When heatproduction and cooling down is in balance a sertain temperature of the rubber it gives .

so the pressure-rising is courced by the temperature difference wich is needed to cool down the tire,

Read once on a forum form one who knows about it,that tires are tested to can stand 2 to 3 times the AT-presssure.
So dont worry about the pressure being higher warm, and dont lower it when its hotter outside .