a 20 degree change is enough to trigger a warning....
and from what I remember, a 6% change in pressure is enough to trigger the TPMS
Just fill all 4 to the appropriate pressure and reset the TPMS
2008 335xi Jet Black
Procede V5//VRSF DPs//AMS FMIC//KW V1//M3 Sways & Sub Bushings// Alpina AT flash
Apex EC-7//Hankook V12//Dinan CAI