My new Tires are filled with Nitrogen

Now I realize how dumb I was to get my new Tires filled with Nitrogen. So now if my pressure goes down, how do I fill them up? With regular Air?

Yes, regular air will be fine.

By the way, I hope you didn’t have to pay for the Nitrogen. It is not worth the expense. Don’t believe the hype.

Yup. Regular air is 77% nitrogen. Air and nitrogen mix just fine.

As a matter of fact, in reality the tire was filled with regular air when they put it on the rim. Then they just added more nitrogen to the mix when they pressurized it. The air that was in the tire when they mounted it, the air that was in it on the rack, is still in there!

Don’t feel “dumb”. This marketing ploy is the latest in misrepresentation.

No problem mixing, as the others have said. This highlights another problem with the nitrogen scam - folks with nitrogen in their tires will be reluctant to fill up with ‘just’ air, resulting in poorly-maintained tires.

You make an excellent point that hadn’t occurred to me. Perhaps this marketing ploy isn’t harmless after all. Perhaps people will drive around with low tires until they get a chance to have it repressurized with nitrogen at the tire store rather than simply adjusting the pressure with the gas station pump.

In bad weather in the winter this could make the difference between a safe drive home and an accident.

You know, a thought occurred to me- they really need to come up with a snazzy trade name for this “product”. Nitrogen is just too pedestrian. Too bad Evian is already taken…

And, remember, Evian spelled backwards is…Naive!


As has already been said, as long as there was no extra charge for the nitrogen, then no harm, no foul. And, it is perfectly safe and appropriate to refill the tires with good old plain air.

What is nitrogen supposed to do differently than “regular” air which, as someone already pointed out, is mostly nitrogen anyway?

Just google it, with the knowledge that all claims are either 1: untrue, or 2: meaningless for normal driving.

Costco provides information in paper at time of purchase and clearly on their tire website indicating the acceptability of regular air until the next tire rotation. As always, it is up to the human to read the info provided.

The marketing ploy is that since nitrogen molecules are slightly larger than oxygen, they permeate the rubber slowly and better maintain pressure.

Bull. Only 22% of the regular air is oxygen anyway, all but about 1% of the balance being nitrogen. Unless you have a slow leak, periodic checking of your air pressure should be done anyway.

They also point out that race cars use nitrogen. Race car tires are much softer and thinner than road tires, and race cars operate on the critical edge of adhesion and are, because their suspensions are rock hard, far more sensitve to tire pressure changes. And, more importantly, race teams have to be concerned about oxygen potentially feeding a fire in the pits, which nitrogen will not.

VDC, this morning I would have agreed that it’s a harmless marketing ploy, but then I read Texases’ post that it could cause people to drive around with underinflated tires thinking they have to get to the tire store to get nitrogen put in. In winter weather than could cause an accident. Proper inflation truely makes a difference on snowy roads. Perhaps it isn’t totally harmless after all.

Slightly more stable pressure changes related to temperature and slightly less air loose through the rubber.

The one slightly worth wile is a reduced moisture content.

“The one slightly worth wile is a reduced moisture content.”

I’m skeptical that there is any value. My rims get awfully wet outside the tire bead. I doubt that the small amount of moisture in air will harm the rim inside the bead.

Tire stores hoped it would turn into a “Profit Center”. They had some shelf space, so they added another product…

they permeate the rubber slowly

Tires are constructed using a butyl rubber innerliner that is impervious to atmospheric molecules like N2 and O2. Air loss is due to valve leakage or imperfections/porosity in the wheel material or the bead to rim seal.

Only 22% of the regular air is oxygen anyway

It’s only 20.95% O2 but what’s a few molecules between friends anyway :wink:

mountainbike–You may be right about that.

Although it would be a sad commentary on the common sense and/or the scientific knowledge of those drivers, it is possible that some people would drive on an underinflated tire until they were able to get to a “nitrogen filling station”.

Even though most of us on this forum realize that nitrogen and regular air are not very different and thus can be mixed without problem, I’m sure that there are people who mistakenly think that mixing nitrogen and regular air would be dangerous. After all, one former member of this board (you know–the one who answered every question about a GM vehicle by telling people to buy a Ford) actually believed that nitrogen was combustible!