[carbo56]

I just changed 2021 M550 to my winter setup. Summer is the standard 19" staggered 245/275, and winter is 19" 245 square. I went to change the tire settings in the TPM, and could not find an option for the winter tire size. All it would show is "Other tires", and as a result, it does not display the target PSI.

I went to the TPM settings, selected "Tire Selection", "Manual", and then "Winter/All-year". The only option it gave was "Other tires". My 2018 M550 would give me the various options for 18", 19", etc. and then it would give the target pressures on the screen.

Any ideas? I guess I need to call the genius.

In the meanwhile, the manual says go with 38 PSI all around for the 19" 245 M+S, so that is what I did.

Thanks.