Tire pressure gauge readings - what to believe?

[cyranodabum]

I want to set my tire pressures to 38 psi cold. I’m getting different readings off my valve gauge vs the TPMS (and frankly, vs my trusty old Goodyear inflator, which has always been wrong). Is this a common thing, that the reading at the valve stem is different from TPMS? And if so, is TPMS more accurate?

I inflated in the evening, so maybe the tires at the time weren’t cold cold yet. And I measured TPMS this morning. But I’m in SoCal, so how cold is overnight cold anyway.

My tires are 285/70R17 btw. Maybe that’s another possible cause? But I’m assuming if there was any TPMS calibration needed, the wheel installer would have done it.

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[TacoFreak]

Inflators are almost always wrong - it may be required by law. lol

You have wheel pressure sensors which have moved and might not have been recalibrated, that sounds like a possible cause of this to me. If it is a good quality gauge and the tires are cold, I would go by that and then get the wheel sensors checked.

 

[Sagebrush]

 

[Miqie]

I bought this gauge at Harbor Freight. It got good reviews on Project Farm. I don't go by TPMS other than general guidelines. If all the tires are usually 32 and suddenly I see one at 26 on the TPMS, then I know there's an issue. Guage

 

[bresna]

I watched this video and thought, "The NFL thought Tom Brady was the reason their air pressures were off?"

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