Tire pressure at AltitudeI also asked Toyota about this: My Highlander had a way to reset the tire pressure system so as to teach it that one was at altitude (I live close to 10000 feet). Without doing that the air pressure readings on the display will be wrong, as they assume 14 lbs ambient air pressure, when it is only 10 lbs up here. Toyota says there is no such reset on the RAV4. Too bad. What this means is that I will eventually get low pressure warnings when there is in fact 4 lbs more pressure than the sensor thinks. Well, the old-fashioned pressure gauges will tell the truth. At least this Toyota has sensors for each tire, which is an improvement on the Highlander's single pressure warning with no indication of which tire.
This is from another thread, but it seems like it might deserve it's own thread. So I tried to look it up, you know, on the internet. O.M.G. Sheer insanity out there. Clearly some folks did not pay attention in high school physics or chemistry. But anyway, it does seem like a valid question, as to how the TPM system in a car deals with altitude. As best as I can tell, you don't need change your tire pressure with altitude. It will, however, change itself. So yes, if you drive to Denver from Seattle, you tire pressure will be higher in Denver, and, (assuming you are going to stay), you should adjust your tires back to the factory numbers.
Looking in the owners manual, I don't see altitude mentioned anywhere in relation to tires. Initializing the tire pressure warning system does look long and complicated. But as far as I can tell, it does not calibrate the system. It only appears to set tire pressure reference level. That is, it sets the notice/alarm levels, based on the pressure in the tires when you started the initialization. Anyway, my guess is that the instrument panel indication of the tire pressure is always correct, and does not need to be reset for different altitudes. Nor would the tire pressure monitoring system. If it was set to 32psi at sea level, it should still be set to 32 psi in Denver.