Checked all four tyres and 3 at 32 psi and one at 31.5 psi. I always use my home pump for all tyres so i have a baseline to work from. This time, the car computer readout was exactly as my LCD pump showed. A RHS rear down half a pound.
It is common in frost for water trapped in the edge of the tyre to freeze and let air out. The car was parked out in rain last night so frozen all over it