According to the Tiretraker website:
12. Why does my manual pressure gauge list slightly different pressures than the TireTrakerâ„¢ TPMS?
The TireTrakerâ„¢ TPMS are highly sophisticated electronic wireless tire pressure monitoring devices. Electronic systems have been proven to report much more accurate pressures that the standard tire pressure gauge. We suggest that you utilize your manual gauge to periodically check your tires, but to rely on your TireTrakerâ„¢ TPMS for better accuracy.
If it still worries you then call them at 866-200-9773. The T-500 warrenty is limited lifetime.
