TPMS data doesn't match manual gauge

[WyomingEV]

My car TPMS says my wheels are at 38psi but when I use a gauge to measure them they show 42psi....thoughts?

 

[rwiegand]

Tire gauges are notoriously innaccurate. Either just accept the +/- 10% is likely to be as close as you're going to get, or try a half dozen different ones and use the one closest to a median value for your best shot at accuracy. Then test it repeatedly to get an idea about precision. I'm sure there must be gauges out there that are both accurate and precise, but they're probably not found at your local auto parts store.

Most TPMS sensors are claimed to be accurate to +/- 2-3%, so plus or minus a pound at 42 psi. I couldn't find anything about precision of repeated measurements with a TPMS sensor.

 

[804son]

Just compensate and fill the tires to the level of the TPMS that you want, Only because that's the sensor that will go off and bug you when your tires are low.
Edit: I'm often filling my tires to +3 - +5 on the tire gauge to get the right temp in the TPMS.

 

[WyomingEV]

Thanks for the info.