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Alfred622's avatar
Alfred622
Explorer
Aug 11, 2018

TPMS - Newbie worried about what it shows.... is it OK?

I just added a TPMS to the motorhome. I've inflated front tires to 85# and rear to 95# which is 5# over recommended inflation based on weight they carry.

TPMS reads them cold as:
Front: 84 84
Rear: 94 95 95 94

Temperatures of all tires were close to 73 degrees (ambient)

Then I went driving for 30 miles and I see for PSI:
Front: 94 94
Rear: 105 108 109 105

and for temperatures
Front: 99 97
Rear 100 91 95 102

I'm concerned about the rear tires....

Right rear tire gained 14 PSI and outer 11.
Left rear tires gained 13 PSI and outer 11.


Outer tires ran hotter than the inners

To those with more TPMS experience than me, do these numbers look reasonable to you? If yes, what type of pressure or temperature change would you find significant?

I very much appreciate any advice those much wiser than I could offer.

26 Replies

  • Everything you posted is absolutely normal for tire readings cold vs hot, don't worry about it.
  • Big Katuna wrote:
    Maybe sunlight affected the outers?
    Definitely.
  • On a crowned road, the inner rears carry more weight than the outer.
    Maybe sunlight affected the outers?
  • That sounds about normal for Summer temperature increases in hot weather. As long as you set the base tire pressure per the WEIGHT of your coach by the scales, when fully loaded, plus the 5 pounds, you should be fine.
    If you go to your tire manufacturer's website they probably talk all about pressure increases due to temperature.
  • The increase in psi seems excessive for 73°- but then I have 22.5" tires. I'd check it with another gauge. What brand tpms are you using?

    I don't think it's a great idea to be over-inflating.