Cold Tire Air Pressure

[GWTimmons]

Always check tires when cold...in the morning...it's not necessary in the day, they will expand as they get warmer, and level back out at night. I run the same speed, and 100 psi is okay. My recommendation is 82, but I noticed wear on outside edges, so the tire expert told me to run 100 psi cold...just like the instructions on the tire.

[GWTimmons]

Sorry, the manufacturers recommendation is 82 psi

[Teamfour]

Ambient temperature is only one influence on tire temperature. Road surface temperature also plays a part. If you have temperature monitoring on your TPMS, notice the change in tire temperature, and subsequent tire pressure, between black asphalt and grey concrete. Having said all that, if my tire pressure is down slightly on a cold morning I just drive to get some rolling friction going which will bring the pressure up. Ever wonder why us racers start with lower pressure before a race?

[Witch Doctor]

Originally Posted by Teamfour

Ambient temperature is only one influence on tire temperature. Road surface temperature also plays a part. If you have temperature monitoring on your TPMS, notice the change in tire temperature, and subsequent tire pressure, between black asphalt and grey concrete. Having said all that, if my tire pressure is down slightly on a cold morning I just drive to get some rolling friction going which will bring the pressure up. Ever wonder why us racers start with lower pressure before a race?

Nope never new or wondered that. but what do you call down slightly on a cold morning? I do wonder that?...

[W5CI]

It says on my tires to set pressure with tires cold, which is what i do. it doesn't matter if it is morning or nite time as long as they are cold. ambient temp is irrelevant IMHO. My tires will gain at least 10psi when running 65, and more if on asphalt highway , the sunshine will add a couple of lbs over the shady side of TT

[gfarmcafe]

Originally Posted by Teamfour

Ambient temperature is only one influence on tire temperature. Road surface temperature also plays a part. If you have temperature monitoring on your TPMS, notice the change in tire temperature, and subsequent tire pressure, between black asphalt and grey concrete. Having said all that, if my tire pressure is down slightly on a cold morning I just drive to get some rolling friction going which will bring the pressure up. Ever wonder why us racers start with lower pressure before a race?

Agree. Also, when traveling north or south, the side facing the sun will be warmer than the other. I check and adjust pressures before travelling and I'm not worried as long as the TPMS shows consistent pressures and temperature throughout the day.

[Scheinin]

Originally Posted by DreiHunde

Get the popcorn ready boys! Its about to get interesting up in this place!

You have here a person who has only 7 posts asking a serious question. You probably did not know the answer when you had 7 posts.

[gfarmcafe]

Originally Posted by Scheinin

You have here a person who has only 7 posts asking a serious question. You probably did not know the answer when you had 7 posts.

Now, now, now. Get a life and enjoy the humor in all of these opinions. It just shows how diverse and concerned everyone is. Who knows, maybe the OP will get a good answer with one of these posts that might actually save his/her life.

[IHDRIDER00]

If I set my Tire pressure at 80 on a cool morning and drive through the hot afternoon the pressures will rise to the upper 90's is that OK?

[Ford Idaho]

Originally Posted by IHDRIDER00

If I set my Tire pressure at 80 on a cool morning and drive through the hot afternoon the pressures will rise to the upper 90's is that OK?

Yes!

[spock123]

My camper tires says max 110 lbs and I normally run them close to that. Anyway once the tires heat up they will be at 110 lbs pretty quick. I don't try to get each tire at 110 lbs cold. My truck tires are 80lbs max but I run 80 lbs rear and 60 lbs front. I could run less lbs per tire and I'm pretty sure the tires wouldn't know it. I sometimes run less than 110 lbs in camper tires and everything works great.


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[Rango]

Thanks Gang ... I knew I could start some conversation here.

My tires say 110PSI cold and I have always started with 100PSI the night before leaving. So I'll just keep doing the same thing I have been doing the nite before, then go inside, have some bourbon and get up in the morning and head out. I'll turn off the TPM alarm until the tires round out and warm up a little then keep an eye on things. I've read so much about these dang tires I did not want to spend my entire retirement worrying about them.

Enjoy your popcorn and thanks for the input.

[Blackhat6mike]

When I first bought my TST 507 system, the lady with the company helped me program it, told me that a 30% increase in tire pressure is where the alarm should be set ie: 80psi cold should be ok up to 104 psi and the max temp to 155 degrees. That is how I set up my system and it has served me well. I have seen as high as 98 psi on a trip through the Florida Keys in summer. No big deal.
The tire manufacturers figure in the increase in psi/temp, thus the stamped cold psi settings. So MANY people worry more about too much pressure when its underinflation that causes the most damage and failure.
Setting your pressure to REACH the "max cold psi setting" when they warm up, is compromising the "planned" increase. This is counter productive to the manufacturer planned results.
OBTW, Maxxis M8008 all around.

[18CrewDually]

I only check the tire pressure at night in the winter, since it's the coldest.

[racer4]

Hi all,

FWIW, I had my tires loads weighed individually at the FROG rally and the heaviest tire weight load was 600 lbs more than the average tire weight load ((total FW weight - pin weight)/4).

The heaviest was the left front, under the refrigerator and kitchen cabinets.

After reading a ST tire forum discussion started by a tire engineer and RVer, I keep my ST tire load inflation weight capacity at least 15% more than the actual weight on the tire ("Reserve Capacity").

Combining that with one tire weighing way more than the average, I keep the tire inflation no less than the stamped max load inflation of 110.

I am not the weight police, but I hope you all are factoring in the variance of individual tire weight loads when deciding the tire inflation.

[Teamfour]

Originally Posted by Witch Doctor

but what do you call down slightly on a cold morning? :

No more than 5 psi.

[waiter21]

At sea level, pressure will change about 2% per 10 deg F.

If you start at 100 psi at 80 degF the pressure may lower to about 90psi at 30 deg F (about 2psi per 10 deg)

Measure the tire pressure in the morning and see if this is close (the 90 psi estimate). Also - What pressure is your TPMS set to alarm.

[Dr-G]

I would change to upper limit of the TPMS.

I was doing research before I bought my system and a source (tire manuf) stated in testing tires reach something like 120 degrees before they fail. I forget where I read it but I think you can certainly move your temp range up a bit.

Mine change at the most 8 degrees and 8 pounds of pressure.

[gfarmcafe]

I guess I'm missing something, but I'm more concerned with gradual loss of air pressure, or traveling at highway speeds with lower pressures, which causes temps to rise to dangerous levels. I've found the temps in the tires will run about the same as the outside temps if they are set at the recommended cold air temperatures. So far, this has worked for us with the tires having about 10,000 miles. Oh, they're all made in China, so start popping!

[SidecarFlip]

Originally Posted by emm-dee

I don't care what anyone thinks. I'm still going to use a 78% nitrogen mix when I bring my tires up to recommended pressure.

So do I, and I bought a set of red valve caps to be different.