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k9dad's avatar
k9dad
Explorer
Feb 26, 2018

Maximum Tire Pressure

Hello all,
I have 235/80 R22.5G XRV Michelin Tires. The side wall states it has a maximum tire pressure of 110 psi when inflated cold. I inflate to 105 psi for the front and 100psi for the rear tires. When traveling down the road, my tire pressure monitor (TST) showed 114 PSI for the front tires. Is this unsafe or normal heat expansion calculated by Michelin? Please don't respond about weighing the RV and getting actual PSI's as recommended by Michelin on their chart. Just want to know if the reading above 110 PSI after the tire is warmed up is safe or not. Thanks for your replies.
  • I was running 100 psi in mine because that what the previous owner suggested, I needed a front end alignment and Redlands Truck and RV also weights each wheel and axle individually and gives you a print out, they recommended 90 psi and adjusted them accordingly. WOW what a difference so much smoother !!
  • You asked a good question about tire pressure! I own and drive on the same type tires as you, and have had extremely good luck running 100lbs. all around. I did a lot of experimenting to find what worked for me! Michelin & Winnebago recommended 90 lbs. front and 85 lbs. rear when my coach was new in 2004, that combo didn’t work for me due to tire squirm.
  • I lived and breathed tire pressure issues for 8 years when I sold PressurePro TPMS. Putting the pressure at the value on the sidewall has most RV's running around on tires that are too hard. I know that the tire pressure you should use is not a fixed value you can find anywhere for your brand tire, but there is one sure way to find out. Each owner needs to weigh their rig. Ideally, the weight of each wheel, or set of wheels, would be determined. Since there are few scales that will allow you to position your rig to make this happen, the next best choice is to weigh the front and rear wheels separately. Truck scales will allow this. Once you have these data, go to your tire manufacturer's web site and look for Load-Inflation Tables for your tire to get the pressure your tires need to support the weight and give you the most comfortable ride possible. The reason "one size does not fit all" is the way each owner loads his rig. Speaking of this, look in your 'basement' and try to even out the load from side to side. It will make a difference.
  • As Ron said, max sidewall is only for max weight. I ran max sidewall on my new Yokos (125 psi) until I could get the rig weighed and found the tire manufacturer's chart said I could run 90 psi. I added 5 for extra cushion. The difference in ride was incredible. The bridge joints didn't jar the coach as much and there was less lane movement when the semis went by.

    Running 95 psi, my TPM get up to 109 on the road.
  • If you carefully read what it says on the side of your tires, you will find that it gives the air pressure that is needed to carry the MAXIMUM amount of weight that your tire is designed for.
    If you plan to carry the MAXIMUM amount of weight, and you inflate your cold/un-driven tires to the pressure printed on the side of your tires, your TPMS will still show that the pressure increases as soon as you start driving. This is normal and well within the design parameters of your tires.
    What you do not want to do is release air from your tires, after you have driven on them, to lower the tire pressure to the maximum pressure for the maximum weight to be carried.
    Tire pressure is always set on tires that have not been driven and are based on the actual weight to be carried, as determined by a four corner weight of your RV.