I just got my new wheels and set the tirepressures.

I have x2 (same make brand) digital pressure readers made by Accutire and they both read identically.

My TPMS sensors are telling me that there is a 2 psi difference (low) than what I set with Accutire gauge and the readings fluctuate slightly with TPMS.

I also have a newer analog gauge and though not electronic reads very close to Accutire.

I was wondering:
- anyone ever notice this before ...im sure it has come up.
- how accurate is TPMS vs other gauges
- anyone recommend a good quality digital pressure reader to try out.
- recommended pressure for 20" wheels 245 fronts / 325 Rears - i am running 36/39 psi right now.
- how often the TPMS sensor "reads" or polls the info...is it instantaneous? from what I can tell it is not.

Thanks

 

I was wondering the same thing. I hear there is a process in the car manual (mine is 997TT) to calibrate the TPMS. I may have the dealer do that next time I am in there.