[A4] TPMS - Tire Pressure Monitoring System & Cold

[gsackerson at comcast.net]

Hi all,
  I had an odd experience last week with my 2006 A4 that came with TPMS on all 4 wheels, and wondered if anyone else had experienced this. We had a real cold spell, where the temps got down to single digits during the day and minus temps at night. When I got into my car after my carpool ride, the Tire Pressure Monitoring System warning lights came on. I ventured over to my dealer to see if they had heard of or seen other cars do this when the temperatured dropped significantly, and they told me they had seen a few instances of this. We recalibrated the system, but the concern I have is, this now represents the new median temperature to compare against (I assume.)

So, this begs the questions as to the use of TPMS technology:

(1) If the temperature gets either much warmer than the calibrated mean or much colder, does the air pressure in the tires vary enough to make the TPMS think there's a tire(s) with low pressure?

(2) If you recalibrate to get the warning lights to go off, I assume that sets the new mean temperature and the same problem could occur when we go from winter to summer.

Any thoughts? The salesman who helped me recalibrate told me the experience I had is one reason he's not a fan of TPMS, but I can see the advantage. If you don't monitor your tire pressure every day (who does) it could help alert you to a slow leak, that may not be visibly obvious (been there, done that.)

Any thoughts?

Glenn