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Nitrogen Filled Tires

I recently purchased a Subaru Outback that has tires filled with nitrogen. I am a fanatic about keeping correct pressure in the tires. Unfortunately the closest place that dispenses nitrogen is 10 miles away and by the time I drive there, the tires are no longer “cold”. Can I buy a tank of nitrogen and do it myself and is this safe?

Measure your tires when cold. Suppose they need an extra 2 psi each. Drive to the nitrogen disenser and measure pressures again. Now add 2 psi to your current readings.

Use the 78% nitrogen product call air. The whole nitrogen in the tyres thing is a lot to do about nothing. The difference for a passenger car is not measurable with standard tools. If it is free and convenient sure go ahead, it will not hurt, but it really will not help either.

waste of time/ use what we have been using since forever

The only tire I own that lost pressure in the last year had a nail through it. I wouldn’t waste any time thinking about nitrogen.

Your tires are not filled with nitrogen. They were filled with the shop’s bay (room) air when they were mounted and then brought up to pressure with nitrogen. Since bringing them up to pressure probably only added some 25% in volume (wild guess) and the room air was about 22% oxygen, you now have about 84% nitrogen and 16% oxygen.

If you now add more regular air, say you add 1% volume, since air is 77% nitrogen you’ll be now be at perhaps 83% nitrogen and 17% oxygen.

I’m rounding the numbers and I’m ignoring argon and misc, as that only comprises about 1% of air.

Nitrogen is a marketing gimmick. A harmless one, but a gimmick.

All you smart guys out there, I cheated and didn’t go back and figure out how much air needed to be added to the average car tire volume to bring it from average room pressure (at sea level at 73 degreesF, 29.92 in hg), but it’s only because I’m lazy. And I wanted to keep it simple. If you want to do the numbers, be my guests. I’ll not be insulted.

And to the guy who made this point on a previous thread (I think it was Craig?) thank you. I stole your idea. Be flattered.

Hey, c’mon guys! The OP wants to put more nitrogen in his tires. He did NOT ask our advice if this is a useful idea or not. Let him care for his car his own way.

Yessir, it’s possible to buy a tank of nitrogen, a hold-down device, and a regulator for a ten-year supply of nitrogen gas for your tires. It’s quite safe. Check your Yellow Pages under compressed gas.

You’re right Steve.

Yup, you can buy a tank of nitrogen and fill your tires. And yes, it is safe.

Thanks to all who responded. I am on the fence on the nitrogen tires still. I live in a hot climate (Arizona) and figured that this was better for the tires based on the temperature extremes we experience. Tires blow here at an amazing rate. My former mechanic advised me to keep them filled with nitrogen based on his experience (he drives high performance cars). Thanks for referring to me as a man but I am a woman who likes to do my own car maintenance as best as I can.

Are you sure that it is safe?

Our friend, Beefy Norm, informed us a few months ago that nitrogen is “highly explosive”, and he seems to be very well informed on many issues, particularly political ones.


Yup, you could even smother a fire with nitrogen (deprive it of oxygen by pouring nitrogen on it).

I know you know that, and I know that you know that I know that you know that, but I didn’t want any visitors to the thread that don’t know that and don’t know that I know that you know that to get confused.

You’ve added an excellent variable to the question. We argue amongst ourselves about this nitrogen issue often, but never really considered those few areas with extreme temperature swings. When I went to basic training in Texas we’d be freezing at night and broiling during the day.

Perhaps in these extreme daily temperature swings every little bit of dryness, every reduction in moisture, helps stabilize the pressure enough to make a difference.

You’re causing me to rethink my assumptions.

No there really is no measurable advantage, even in very hot parts of Arizona.  It is just not worth worrying about and spending the money.  Remember common air is 78% and the other components differ little from nitrogen under the conditions we are talking about.

Now what you do need to do is to make sure your keep your tyres properly inflated.