cpbmd

I was checking my tire pressures yesterday trying to get the fronts to 37psi and the rears to 44psi. It seems as though the tire pressure readout in the instrument cluster is about 3-4 psi below the reading I manually get at the tire with my pressure gauge. Is this normal? I am assuming that my manual pressure reading is more accurate. I am using a $10 tire pressure gauge from Autozone with the circular readout dial.
Thanks for your help.

KeninBlaine

The TPMS on my 07 Targa4S consistently measured about 3 to 4 PSI less than any gauges I used. It was a PITA since it only took about a 1 or 2 pound pressure reduction to trigger a warning. My current car doesn't have TPMS and I don't miss it.

cpbmd

Yeah sometimes too much information is not a good thing. I just checked the cold tire pressured on my 997 C2 with the gauge. The rears are 44psi and the fronts are 38psi. The TPMS readout is exactly 2lbs low for all the wheels. I think I am not going to sweat it and just rely on the hand held gauge readings. Thanks for your input

Mike in CA

My experience has been much different. The TPMS on both my '09 Carrera S and '11 Cayenne S are pretty much dead on with my Porsche and Longacre gauges.

vinnysca

My TPMS on my 09 C2S is also spot on. Having N2O in my tires also keeps all tires consistently inflated to 37/44 respectively.

jrotsaert

Mine is spot on vs Longacre and Porsche gauges

cpbmd

Okay. If that is the case maybe I should get a better gauge like the Longacre and see how it compares to the TPMS. I will report back. Do you know of any good sites where can I order a Longacre guage?
Thanks for your input.

cpbmd

Do you think the LongAcre Economy Digital Tire Guage would suffice?
It is probably better than the dial guage I got at Autozone.

http://www.saferacer.com/longacre-ec...?productid=641

Thank you very much for the tips.

1100S

Be aware that the TPMS on the '09 and newer cars is completely different from the '08 and older. The new models tend to be spot on.

cpbmd

Good point thanks. I think I will just get a good guage, check tire pressures once per week with the gunge and call it a day.
Thanks

hpowders

My humble lil' ol' 2007 997 base TPMS is spot on.

Bob Rouleau

My 07 was consistently off by 3 lbs. The 09 4S and 10 RS agree with my Longacre.

jhbrennan

My 08 is off by 3 psi both front and rear. I've never really paid attention to the absolute number reported by TPMS, only any differential. I inflate using a quality gauge to 34 and 40 and TPMS reads 31 and 37. So I pay attention to any changes from the 31 and/or the 37.

cpbmd

Perfect! That is what I am going to do. I will ditch my autozone gauge and buy a LongAcre Guage then do as you say, paying attention to the differential not the absolute number. Thanks for your help.