colfax

Hello again!

Consistently my dashboard display shows the tires at around 34 yet both of my tire gauges show 36

same thing is true on my 2012 Camry, two pounds more PSI on the hand gauges

is this a known discrepancy, are you all experiencing this?

Gronemus

How do you know how accurate your hand gauges are? They both could be wrong by the same amount. Unless you find some calibrated device to compare them to you will never know which is correct.

BTW, here is a link to a Consumer Report article about pressure gauges. Some useful information there: linky...

Scrutator

My TPMS is highly accurate. Matches my hand-held gauge exactly.

mjeds

I've noticed the same thing over the years form various manufacturers. FWIW typically TPMS is only accurate after the vehicle has been driven >40mph for >2 miles. Fresh start in the morning after sitting all night your TPMS is not going to be accurate, I believe the owners manual even says this.

RussLS460

I doubt 2 PSI either way will make much difference.

jmcraney

The TPMS is inherently accurate and is accurate as soon as it is turned on - it wouldn't work if it wasn't. And, it is accurate over a wide range of temperatures. The pressure of the tires has a positive temperature coefficient of about 1 PSI per 10 degrees F.

colfax

well now I went to AutoZone and borrowed two gauges from them, a digital and a dial

they correlate the same as my stick type gauges

all four readings are about two psi higher than the TPMS

so who to believe?

I am choosing to believe the hand held gauges, just because they are read the same

jmcraney

I don't know about the resolution of your handheld air gauges or your technique, but I am very confident in telling you that TPMS sensors are as accurate or more accurate than any of your handheld gauges. If you prefer to verify this yourself I can suggest a brand and model hand gauge that is accurate and has high resolution that cost about $60.You have to keep in mind that the tire pressures have positive temperature coefficients of about 1 PSI per 10 degrees F. If you want to compare a handheld gauge to the TPMS sensors, you would need to do that, in the morning before you drive the car: Inflate all tires to the same pressure, using the handheld gauge, and then, in short order, turn on the car's ignition and without driving the car, log the pressures that are displayed in the dash and see how they compare to each other, and to the handheld gauge.