Guess maybe I've heard of this 1 time in my adult life. A friend took notice of the green valve stem caps on my Sienna. He asked if I run nitrogen in my tires. Beats me as they've been there sinse I got the van. He claims the tires are nitrogen filled. Havn't a clue why they do this. Any idears?

It does not expand with heat like air.

Supposed to be better for the ware on the tires.

Equalized air pressure, is my guess. The earth's atmosphere is mostly nitrogen, even though we're oxygen breathers. Oxygen is only 21 percent of the air, whereas nitrogen is 78 percent. The rest is trace gases.

quote:

Originally posted by PR64:
It does not expand with heat like air.

Is this true? Nitrogen doesn't obey the ideal gas law? I thought all gases do.

Dunno about cars, but in airplane tires it is said that nitrogen does not migrate through the tire rubber as quickly, meaning they maintain pressure longer.

A quick google list that, being subject to less pressure changes on temperature change, and being dry. No water vapor also means less pressure changes with temp changes and less corroding of steel rims.

As others have noted, nitrogen does not expand or contract nearly as much as it would with all the other gases in normal air.

Another benefit - without oxygen in the inside, you're reducing oxidation of the internal surfaces. This MIGHT increase the lifetime not directly related to mileage.

Let me check the vintage Ouiji board...

Popular Mechanics explanation.

https://www.popularmechanics.c...4/nitrogen-in-tires/

Well, its got aluminum alloy factory rims. If nitrogen is more better to run, how does one go about useing it to fill new tires? Where do we get nitrogen?

quote:

Originally posted by David Lee:
Well, its got aluminum alloy factory rims. If nitrogen is more better to run, how does one go about useing it to fill new tires? Where do we get nitrogen?

The nearest airport?

I thought tire shops stopped selling it because people realized it's a scam.

The truth is that bottled nitrogen has much less moisture than the typical tank in a shops air compressor.
That humid air is responsible for most of the extra rise in the pressure as a tire warms up.
As noted earlier, nitrogen is already the largest component in the atmosphere.
Tire places do it as a up-charge item with little practical value to the average driver. Snake oil.

quote:

Originally posted by David Lee:
Well, its got aluminum alloy factory rims. If nitrogen is more better to run, how does one go about useing it to fill new tires? Where do we get nitrogen?

Most tire shops have a machine that filters it from plain air. They usually just deflate a tire and refill it a few times with pure nitrogen to flush out most of the regular air and moisture.

quote:

I thought tire shops stopped selling it because people realized it's a scam.

^^^^^^
This was my thinking as well.

Scam. We use a 78% mix.

Pv=nRT
Snake oil indeed. O2 molecules are smaller than N2, and do migrate through the tires more quickly. So, allow your tires to lose a few psi, then refill with air to desired pressure. Eventually, after a few bleed/refill cycles, you will have pure N2 (and some water) in the tires after the O2 bleeds out.

I'm no great fan of the nitrogen use at my local tire shop. They once did it (without asking) and removed my aftermarket valve stem caps and put on the green ones.
However, the corrosion that using air can cause on alloy rims is very real. I've been battling it on my E46 BMW for a couple years.
It was so bad, I had to have them sand and smooth the inner lip (where the tire meets the wheel) in order to not leak out air.

Here we go again. Let's talk about the best oil while we're at it.

I'm going to make some popcorn. LOL

OK thank you all. There seems to be no super advantage to useing it. Its not a Benz its a van. Think I can stay the corse with good old air.

quote:

Originally posted by .38supersig:
I use the same oil in my push mower and Kenworth and it works great!

Well now, the Siennas right rear is running part nitrogen, part regular air and a tall can of Fix a flat. Hope it dont splode..

The magic 8 ball says 'No'...