~(10 psi) low on all tires according to MMI?

[LakeTahoeQuattr]

So I attached a picture for reference. I have double checked and all tire pressures read about 8-10 psi lower than they actually are according to my MMI.

Has anyone else ever experienced this issue?

[LakeTahoeQuattr]

Could it be that when the previous owner installed the 20s (originally 18s) on the car a TMPS calibration was needed... ?

[MP4.2+6.0]

Hi, for what its worth and as an almost a ten year D3 owner over 100K miles, honestly I don't ever recall this sort of scenario with TPMS, literally across thousands of posts on the other leading board for D3, and probably a hundred+ dealing with TPMS. There is no calibration for TPMS relating to wheel size.

Only thing I can think of is as a 2004, car is likely on its third set of sensors. They last 6 years or so. Thus 2003 or 2004 in service from first sale, plus 12 years for two sets = second set clocked out by about 2016. Given age of at least the older ones, many/most D3's are probably either disabled for TPMS (via MMI for some, or VCDS in any case), the not working TPMS light is on, or they went lower cost aftermarket on the sensors. I actually stuck with OES, but my sense is I am in the less than 10% who probably did. Then in turn if you have some brand du jour/no name/who knows what brand inside those wheels sensor wise, all bets are off. Or rather, with this theory you sort of know...likely not OES and apparently not accurate by a wide margin. OES was Beru BTW, which sold the business resulting in the current branded Huf ones being the OES type. Of course I assume your other gauge used as a reference point is itself accurate.

[tsuter]

Have you checked with multiple tire pressure gauges? Yours might be bad?

[LakeTahoeQuattr]

I have checked with multiple gauges.

I checked the service records, they were replaced in 2009 with revision C sensors, newest is revision E. Most likely error due to low battery and they should probably be replaced.

I like the TPMS because it informs me if (1) tire is outside a parameter and sounds the alarm. So at this time it still does that feature. Sadly since the pressures are less, the differential is amplified and causes "false alarms" with less change in pressures.

This is a first world problem and once they fail entirely I am not going to replace them on a 15yo car if they are $200 (ea) not worth it.

Thanks for every ones input!