And to all a good nitrogen

The new tires were installed yesterday, and to demonstrate to the shop that I wasn’t a complete idiot, I came up with the recommended pressure — 33 psi front, 30 rear — without reference to the usual decal in the door, which for some reason isn’t in Gwendolyn’s door at all, but under the console lid. I was, however, unable to supply the torque for the lug nuts (85 ft/lb), and then the next question floored me: “Would you like these tires filled with nitrogen?”

Say what? Is there a Clean Air Alert today or something? “What’s the advantage?”

Some of these points were raised.

And inasmuch as I’d gone through an entire World Tour with a slow leak, which, once repaired, leaked faster, the pitch about better pressure retention proved persuasive.

It’s not like they’re having liquid nitrogen piped in from the Space Station at three hundred below or anything: apparently there are new gizmos which can separate the components of your garden-variety compressed air. And in reviewing the literature, I decided that it’s not that nitrogen itself is so wonderful; it’s that the oxygen (twenty percent or so of said air) is a pain in the belt.

Besides, Click and Clack make fun of the whole idea, so I figure the least I can do is give it a spin, as it were. And no, it doesn’t void the warranty.

As for the tires themselves, which for all I know could be filled up with vaporware and old campaign promises, well, it’s hard to make much of a judgment call after 25 miles, but they’re definitely less squirrelly than the BFGs they replaced. The noise seemed a bit high on some of Oklahoma City’s last-century asphalt, but they were weirdly quiet going over the Crosstown. The most obvious characteristic, though, is that rubbery smell that managed to fill up my garage in mere seconds and which I expect to linger for some time.


  1. Mark Alger »

    18 August 2007 · 5:36 pm

    Take a spin through Wikipedia, just for grins, and see what the composition of the atmosphere is. Did they charge you extra for this nitrogen inflation?


  2. CGHill »

    18 August 2007 · 5:57 pm

    Yep. Six bucks a tire. On the other hand, I got these super-studly valve-stem caps with a futuristic logo, which offsets the price by a couple of cents.

    The first trip on the Dunlops was back to work, where I introduced the following question: “If price were not a factor, would there be an advantage to inflating the tires with a really inert gas, like argon?” I think we decided that the extra mass of the heavier gases would be detrimental to handling, though helium, which is lighter, wasn’t brought up.

  3. triticale »

    18 August 2007 · 8:36 pm

    The atmosphere is mostly nitrogen, but there is enough oxygen in it so as to support combustion. Good news for us, not as good for tires. Endurance racers were doing this 30-some years ago; I read about it in coverage of the Sebring 12 Hour race.

  4. CGHill »

    18 August 2007 · 8:57 pm

    Then again, they tell me that the absolute worst stuff you can put in a tire is that canned-inflator gunk: you spritz it in and it spatters all over the inside of the tire, and if the hole actually gets sealed it’s purely coincidental.

    I still carry an air pump as part of my emergency kit, along with one of those reflective triangles, a set of jumper cables, and a roll of duct tape.

  5. Jeffro »

    18 August 2007 · 10:02 pm

    NASCAR uses nitrogen in their racing tires because there is less pressure variance than atmospheric air as the tires heat up, giving more consistent handling characteristics.

    Will it benefit Gwenlolyn? It sure can’t hurt to try.

  6. anomdragon »

    19 August 2007 · 8:01 am

    Charles, They have also used nitrogen in aircraft tires because of the stability and it runs cooler so I have been told. Helium and argon are not used because of pressure fluctuations with changing temperatures.

  7. TheCannyScot »

    21 August 2007 · 9:21 am

    It took me a few minutes to come up with what BFG really stands for. Those first two letters took me down a whole different path…

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