Tire pressure monitoring system
Posted: Thu Jan 20, 2022 11:06 am
A couple of questions about the BMW TPM system for the BMWBMW tech gurus:
What is the difference between "Tire pressure within the permissible tolerance." and "Tire pressure within the limit range of the permissible tolerance." ? This comes from the Technology in Detail section of my owners manual.
The bigger question, regarding temperature compensation: Let's say the ambient temperature is 40 F and I fill my cold tires to the recommended 36/42 psi. During the ride, my TPM reads 39/45, which I always assumed was normal, and so ignored. However, if those TPM readings are compensated to 68 F, that means I had actually over-inflated my tires and should actually have inflated them to 33/39 at 40 F, so that the TPM would read 36/42 when warm.
Am I off the mark here?
Thanks for your help.
Henry
What is the difference between "Tire pressure within the permissible tolerance." and "Tire pressure within the limit range of the permissible tolerance." ? This comes from the Technology in Detail section of my owners manual.
The bigger question, regarding temperature compensation: Let's say the ambient temperature is 40 F and I fill my cold tires to the recommended 36/42 psi. During the ride, my TPM reads 39/45, which I always assumed was normal, and so ignored. However, if those TPM readings are compensated to 68 F, that means I had actually over-inflated my tires and should actually have inflated them to 33/39 at 40 F, so that the TPM would read 36/42 when warm.
Am I off the mark here?
Thanks for your help.
Henry