How Accurate Should TPMS Sensors Be?

[DRS 95 Silverado]

Brought a '14 GMC a while back. My tire sensors all seem to read about 4 lbs. lower than they should. I have tire gauge I have tested with another test gauge. I checked tires this afternoon, been sitting in a unheated garage, probably 35 - 40 degrees and they checked about 34 lbs. but DIC has only been showing about 30 when I first take off. Do they make them read low on purpose?

[sams819]

Mine are within one pound using a race car gauge. It is real accurate.

[mike94silverado]

same here mine are within one pound no matter what manual gauge I use

[DRS 95 Silverado]

Thanks, I'm going to check my gauge again and I might let the dealer check tires with their gauge. Got it going in this week for the recall anyway.