What percentage pressure change have others had before the warning appears? Yesterday I had one about 100 miles from home. After I parked the car I checked the tyre pressures after leaving them a few hours to cool and found them all around 10% low compared to what I originally stored. Having pumped them all back up I then reset the TPMS to store the values. The question is this: what has the system actually stored? The car wasn't moved between inflating the tyres and storing the values.