Pretty confident my pressure gauge is accurate - I also installed an Xtrons head unit with a TPMS using valve cap sensors and the TPMS readings matches my gauge.

Euro tire pressures on the door edge are 2.2 bar (32 psi) front and 2.4 bar (35 psi) rear for a lightly loaded car - this is pretty much what I run. Do US spec cars with 20 inch wheels run the same pressures?