Has anyone else checked the altimeter? I have a 2007 GX 470 and the reading varies from 450' above sea level to -150' below sea level. I always check it when I park in the same place next to my garage door. And since my house is relatively stable I wondered why there is such a large difference in the readings. The owner's manual simply states it will vary due to barometric pressure changes.

Like you said, the altimeter is based on barometric pressure, so its not accurate. Barometric pressure can change as weather front moves thru or when you are going from on city to another. The altimeter is useful say if you are going up a mountain, you can see how high you have gone up. For a accurate altimeter reading, I would use a GPS.