from the FAQ:

- The tire pressure monitor system measures wheel speed at each wheel, and uses the outside ambient temperature to compensate correction for density. if a tire's pressure is low, you will be notified by a signal in the instrument cluster.


Interesting, so this is to say that it monitors the tire pressure without a actuall pressure sensor? What if you had one tire that was very worn [and thereby slightly smaller]. Would the system say that tire was low on air since it was rotating slightly faster then the rest of the tires?

 

Does the pressure monitoring system warm you if the pressure is more than the normal amount?

 

Looks like TPMS only detects drastic changes in pressure of one wheel. With recent temperature drop I checked tire pressures and on of the front wheels was at 22psi, others were at 24-26-28. TPMS did not go off, probably because of the gradual pressure drop. So it makes sense not to trust the system completely. Keep a tire gauge handy.

 

3 of my tires are slightly worn and one of them is brand new, so the tire light is always on for me now(even if i turn it off it comes back on i like 10mins of driving)