Nitrogen v. air in tires...

Dear Car Talk

Dear Car Talk | May 01, 1992

Dear Tom and Ray:

You two dispense a lot of hot air. What is your opinion about using nitrogen instead of air in the tires of personal vehicles?

TOM: Well, Bob, I can tell you're a card carrying member of the Nitrogen Users Technical Society (NUTS). And we want you to know we support you in your efforts to promote the increased use of nitrogen.

RAY: In fact, we've been encouraging all of our readers to wear small tanks of nitrogen on their belt loops. I mean, you never know when it could come in handy. You might suddenly find yourself in an oxygen rich environment, and if you have your personal nitrogen, you'll be prepared to take action and dilute it.

TOM: Actually, Bob, if you really want to get technical, there are a couple of advantages to nitrogen. First of all, bottled nitrogen contains no moisture at all (unlike the air that comes from the gas station's compressor). Secondly, pure nitrogen, by definition, contains no oxygen (air is roughly 80% nitrogen and 20% oxygen). While the moisture and oxygen in air will eventually contribute to the rusting of the inside of the wheels, pure nitrogen will not.

RAY: If you had a truck, and you had eighteen tires and wheels at $500 a pop, then using nitrogen might be worth it. But we really can't recommend that you go through the trouble for a passenger car. I mean, when's the last time you heard someone say "I had to take my car to the crusher because the inside of the wheel rims rusted away."

TOM: Right. In the grand scheme of things, using pure nitrogen in your tires hardly seems worth the effort or the expense...unless, of course, you can steal it from the place where you work!

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