Valve Stem Caps w/ Nitrogen Label

That whole nitrogen thing is a bunch of bunk. My dealer put little green rings around the valve stem, and then screwed the regular old black caps on. Only problem was that they only inflated the tires to 28 PSI. I immediately upped them the 42/40, and couldn't care less about nitrogen. If it goes away or leaks or gets contaminated with regular old air I don't care. I check my tires weekly and can't be bothered with some hokey nitrogen thing.

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If the N2 fan claims are true, then the oxygen will leak out of your tires and leave you with just N2 in your tires with no effort or $ on your part.ound:

 

I have always used 78% nitrogen in my tires with good results, and it's fairly inexpensive.

 

Air in tires usually expands about 1psi per 10 degrees F. N2 a little less but not enough to make any difference. Check your tires cold and let them go up when they get warm, that's what they are designed to do.

My opinion, N2 makes sense in aircraft tires and race car tires but offers no real advantages for street tires. If you get it free, such as at Costco, fine; if they want you to pay extra for it I would say no thanks.

 

I check my tires so religiously that it just doesn't matter. I easily check my tires at least once a week, have done that since I started driving 40 years or so ago. It makes a huge difference in handling and mileage.

If it doesn't make a difference in handling or mileage, then as far as I'm concerned it's worthless. If you're the kind of person that gets his tires checked by the mechanic at oil change time only, then maybe N2 is at a slight advantage over just plain air.

Not only that, since my brand new Prius came with 28 pounds all around, I'm pretty sure that the dealer wouldn't put my requested 42/40 in the tires as I did.

I have a compressor in my garage ... N2 is far away at the dealership ... no thanks.

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When you say 'oxygen', I'm guessing you're talking about regular old air, which is only about 20% oxygen, almost all the rest is nitrogen totally for free .... about 78% worth .... all at no charge ... as tumbleweed mentioned ... good one TW !

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That's the beauty of the N2 mythology. If it's correct, that 20% O2 in the air soon leaks out and leaves you with only N2 so no need to buy N2.

If the N2 mythology isn't true, then there is also no reason to buy N2 for your ties.

 

Me too. If O2 and other air gasses diffuse out faster than N2, then I figure my tires act as N2 concentrators.

 

I considered putting helium in my tires, but was afraid the damn thing would flip over and float away.

 

Has anyone ever watched them do a nitrogen fill? Surely just attaching a nitrogen hose to the filler after mounting the tire leaves some "bad" regular air inside.

Without using a tire/wheel sized vacuum chamber to remove all the "bad" air, how could you ever end up with only nitrogen in the tire? After all on a mounted tire there's only one hole to put in the nitrogen and nowhere for all the "bad" air to escape. If you tried to vacuum all the air out in the open prior to filling, the tire will collapse and dismount itself. If a tire place could answer these questions, I might even believe that the tires were indeed filled with nitrogen. Otherwise I call a capital BS on this scam.

 

Good analogy.

 

Other irony...

If O2 can diffuse through the tire, and you really get all the O2 out during a N2 fill, then some O2 from the air will diffuse back in...and equilibrate at about 3 psi partial pressure inside.

Nitrogen is a marketing scam. It does not affect T/P variation.

 

I put sulfur hexafluoride in my tires. The traction I get is absolutely incredible. I can pull 3 g's on a standard test track.

 

SF6, I think that's the stuff that replaced oil used to suppress arcs in HV circuit breakers.

 

The extra un-sprung weight ruins the ride though.

 

We got tires through Costco, on a previous car. Before going in I removed and pocketed the (black) valve caps. So:

They filled the tires to the pressure posted on the driver's door placard, and put on green valve caps. I payed, drove a couple of kilometers down the road to Chevron (free air), raised the pressures to 42psi with regular air, pocketed the green caps and put the old black caps back on.

 

Me too, although I custom blend it with 21% oxygen, argon, and traces of other gases. Rather expensive and time consuming, though.