Fill your leaky tires with nitrogen for free

You’ve probably heard that you can have nitrogen pumped into your tires in a growing number of locations.¬† The theory is that nitrogen molecules are larger than oxygen molecules and are therefore less likely to leak¬†through your permeable rubber tire.¬†¬†Most of us have atmospheric gas (air) in our tires which is made up of 78% nitrogen, 21% oxygen, and 1% other gases.¬† Service stations selling nitrogen for your tires typically¬†fill with¬†a 93% – 98%¬†concentration of nitrogen.

Tires leak in a number of different ways.  There could be a hole in the tire made by a foreign object, a poor seat on the rim, a malfunctioning valve stem, or typical permeability through the tire rubber.  If your tires are leaking air from any of the first three, get your tires repaired.  These types of leaks allow both nitrogen and oxygen to pass.  If your tires are leaking through the pore spaces of the rubber, read on to find out how to fill your tires with nitrogen for free.

The price for filling a single tire with nitrogen ranges from $4 to $10 (USD) per tire.¬† If you have a tire that leaks through the tire rubber, don’t pay for a nitrogen fill up.¬† Simply fill with regular air each time.¬†¬†Here’s the secret: Each time¬†air leaks through the rubber, you lose more of the smaller oxygen molecules than the larger nitrogen molecules.¬† When you refill with air, the nitrogen concentration in your tire becomes greater and greater.

Let’s say your tire¬†requires 100,000¬†gas molecules to fill to the proper pressure.¬† (It will be much more than that, but for the sake of simplicity, we’ll stick with this small, round¬†number.)¬† Ignoring the 1% of other gases, we start with 78,000 molecules of nitrogen and 21,000 molecules of oxygen.

According to the Get Nitrogen Institute, oxygen escapes from tires at a rate that is¬†3-4 times faster than nitrogen.¬† For this example, we’ll assume that with every nitrogen molecule escaping your tire, four oxygen molecules are also lost.¬† Therefore, every time¬†you lose 26,250¬†air molecules from your tire, you are left with pure nitrogen.¬† 5,250 nitrogen molecules and 21,000 oxygen molecules escaped, leaving you with¬†72,750 molecules of nitrogen.

When you refill with air you will replace the 26,250 air molecules with 78% nitrogen and 21% oxygen.  The gas in your tire will now contain roughly 93.5% nitrogen and 5.5% oxygen.  There you have it.  With just one refill of air into a leaky tire, you have reached a nitrogen concentration equal to that which service stations sell for $4 to $10 (USD) per tire.  Each time you refill with air, more oxygen is purged and the nitrogen concentration becomes even greater.

Agree/disagree with this logic?  Let me know.  Curious about helium or hydrogen in your tires?  How about glowing neon in your tires?  Follow this discussion at MTBReview.com.


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2 Responses to “Fill your leaky tires with nitrogen for free”

  1. [...] stepping and liquid nitrogen boost E8600 to 6440MHz!>> saved by merrellems 27 days ago6 votesFill your leaky tires with nitrogen for free>> saved by spricket24 32 days ago1 votesConverted Organics Amino Acid-Based Organic Liquid [...]


  2. Only problem with that logic is that you are also pumping moisture into the tire……which will aid the remaining O2 to create rust…..
    But at the end of the day, it is better to top up a slack tire with what is available than to drive on a slack tire to a location where the N2 is free!


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