Calibrating TPMS for living at altitude

Yea so for customers I have to set them to 35psi warm in my shop, or it will trigger the warning light on a really cold night. It's stupid. Because 35 my gauge is 33psi toyota tpms.

 

Just a note, as this topic has come up previously...

There is a line in the 2021 Tacoma Owner's Manual that sheds some light on how the sensors/transmitters function.
Chap 6-3 page 426, half way down page.

"When the tire pressure warning system is initialized,the current tire inflation pressure is set as the benchmark pressure."

and mid page 427

"Make sure to adjust the tire pressure to the specified cold tire inflation pressure level. The tire pressure warning system will operate based on this pressure level."

Certainly anyone can make their own minds about what these words mean, for me it means the sensors have no way of knowing real pressures absolute or gauge, until the are referenced to some "known" value determined by an external instrument. After that, the sensors transmit the CHANGE from the reference. Cold or hot, high or low.

The Best way to set tire pressure is with a temperature probe across the tread!

 

We have radio gear on Mt Washington 6,288 feet that I service my house is about 650' no issues so I don't care what it is.

 

You are not racing a F1 is 3psi really that important