Altitude affects both tire pressure and the freezing point

Today, we are going to discuss air pressure and temperature and altitude, all of which involve numbers, and you know how that always goes.

Before we get to that, there is an issue left over from a column last week about farting etiquette.

Boy, you people really liked that one. I have advised my grown-up colleagues to go with a fart column every now and then just to keep things fresh.

A number of you pointed out that I forgot to mention the blamethe-dog technique. That’s a nobrainer, and I can’t believe I left it out.

I have a question from a guy who wonders about the changes in tire pressure when he drives to Flagstaff to visit his daughters.

As the altitude increases, air pressure goes down. The difference between sea level and 10,000 feet is about 4.6 pounds per square foot. Phoenix is at about 1,124 feet about sea level and Flagstaff is just a bit shy of 7,000 feet. Do the math. I don’t get paid enough for that.

Also, for every 10 degrees of change in temperature, tire pressure decreases by about 1 pound per square inch. So, going to Flagstaff also will make a difference here.

Second comes a question from a lady in Sedona who wonders if the freezing point of water changes with altitude the way the boiling point does.

As a matter of fact, it does. This has to do with stuff such as volume and air pressure and a process I would probably mess up if I tried to explain it. The freezing point of water decreases with altitude, but it is a small change compared with the difference in the boiling point.