On my X5 in the USA, I believe the TPM works as significant change in the pressure compare to the basis setting. When I picked up my X5 from the dealer, the tire pressure was at least 10 PSI higher than what was recommended in the manual. After I reduced the pressure, X5 showed the low tire pressure warning. So, I reset the setting which removed the warning message. I don't recall seeing any actual tire pressures.

__________________
2011 BMW 740i
2011 Toyota Sienna Limited
2008 X5 3.0 Space Gray (sold)