Should I trust the tire pressure sensor in my truck or a hand held gauge?

Asked by rojo (24179

) November 22nd, 2017

My tires looked a little low. The truck gauge read clockwise from driver front: 33, 34, 33, 32 psi. I checked it with a hand held tire gauge and got 29, 30, 29, 29. I borrowed my neighbors and got the same readings: 29, 30, 29, 29. So I filled all the tires up to 35 psi according to the hand held gauge. The truck automatic gauge read 39, 39, 39 38. So it appears that it is 4 psi different from two separate hand held gauges (one a stick, one a dial).
Which should I believe? The one built into the truck or my old gauge that I have used for years?
Any thoughts?

automotive

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7 Answers

Maybe you need a gauge to break the tie? For now I’d fill my tires in-between the two.

JLeslie (65418

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Were all three used without moving or driving the truck?
Driving the truck will increase the pressure.

Tropical_Willie (31124

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Gauge. The tire mounted ones are subject to all sorts of external issues. Not really to be trusted.

elbanditoroso (33157

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@Tropical_Willie no movement and all measurements within a few minutes of each other.

rojo (24179

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Segal’s law – A person with a watch knows what time it is. A person with two watches is never sure.

I had a digital tire gauge and a pencil gauge and fretted over their disagreement. When the digital’s batteries died, I threw it away and it relieved me of the mental burden.

Call_Me_Jay (13846

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