Nitrogen In Tires!! - PeachParts Mercedes-Benz Forum

Puck · #1 07-19-2007, 10:07 PM

I don't know if anyone here has tried this yet, but my wife has an '04 Pacifica and she just had nitrogen put into all of her tires. It supposed to make the tires last longer, and maybe it does. However, her Pacifica now rides like it has NO suspension!! Before the nitrogen it rode really well, but now it rides like a brick!! You feel EVERY little imperfection in the road. She's tried to get me to put it in my S500 tires, but I think I'll pass on that offer!! I think I'll just let my tires die a natural death!! She paid $40.00 to have that nitrogen put in, and the ONLY good thing about that is if she has a flat, they'll refill the tire for free. I guess if you live where the roads are perfect, nitrogen would be a good idea....but not in MS!!

MB-Dude · #2 07-19-2007, 10:21 PM

Quote:

Originally Posted by Puck

I don't know if anyone here has tried this yet, but my wife has an '04 Pacifica and she just had nitrogen put into all of her tires. It supposed to make the tires last longer, and maybe it does. However, her Pacifica now rides like it has NO suspension!! Before the nitrogen it rode really well, but now it rides like a brick!! You feel EVERY little imperfection in the road. She's tried to get me to put it in my S500 tires, but I think I'll pass on that offer!! I think I'll just let my tires die a natural death!! She paid $40.00 to have that nitrogen put in, and the ONLY good thing about that is if she has a flat, they'll refill the tire for free. I guess if you live where the roads are perfect, nitrogen would be a good idea....but not in MS!!

Nitrogen is often used as a substitute for compressed air in manufacturing plants, although usually in emergency situations due to cost of the nitrogen. I've never heard of using nitrogen in tires in place of compressed air.

The only negative I can think of is that the nitrogen may dry out the rubber a little faster than compressed air. In the semiconductor plants I worked, we had anecdotal and subjective evidence that dry nitrogen dried out viton o-rings at a faster rate than compressed air. Thus, time will tell if the tires last any longer. However, I suspect the tires will simply wear out long before they deteriorate.

As for the rough ride, I suspect the tires are over-inflated. Check that each tires pressure is as specified on a tire pressure label; usually on the driver's door pillar or fuel cap lid. Nitrogen has virtually the same properties as compressed air in low pressure (less than 40 psi) applications. Remember, the air we breathe is 78% nitrogen.

waybomb · #3 07-19-2007, 10:26 PM

Another gimmick. In my life, I've probably mounted 1000 tires on rims. I have yet to have seen a single tire that went bad from the inside out.

BTW - I belive N2 is about 78% of our atmosphere.

Dubyagee · #4 07-19-2007, 10:26 PM

The nitrogen has larger molecules then O2. It will not leak through the tire as fast as O2 (All tires leak air). As far as the rough ride you need to make sure the pressure is set correctly.

Matt L · #5 07-19-2007, 10:52 PM

Air is not pure O2, or our tires wouldn't be happy for other reasons. Air is about 80% nitrogen.

Race teams use nitrogen for their tires because they also use it for their air tools; they can't run compressors in the pits.

Nitrogen is dirt-cheap. $40 to fill the tires with nitrogen is a huge rip-off. That's probably $.50 worth of the gas in there, and no extra work.

There will be no noticeable difference. The drier gas is slightly better, but even racers don't notice it. The difference you feel is probably over-inflated tires.

waybomb · #6 07-19-2007, 10:57 PM

Holy crap! I did not notice the $40 charge! We buy large bottles of compressed N2 for something like $13 a bottle, and that's high purity gas for food manufacturing. Could probably fill a few hundred tires with one bottle.

What did PT Barnum say??????????

forp · #7 07-19-2007, 11:17 PM

Our local Costco uses nitrogen in all new tires. The reason is the moisture content. The moisture in the tires expands and contracts at a higher rate than dry air(atomospheric or from a bottle). If your compressor could remove all of the moisture, you'd get the same effect. The higher the moisture content, the more the tire pressure varies with temp. It is not snake oil but a good way to help maintain constant pressure with changes in temperature.
Dan

Kestas · #8 07-20-2007, 11:20 AM

Quote:

Originally Posted by forp

... The reason is the moisture content...

I guess I could take advantage of the sunny, dry, -10°F days of January here and exchange all the air in my tires with a regular compressor and achieve the same thing (or better).

When the shops fill tires with nitrogen, how do they flush out the original air that's in there? On a humid summer day that can leave more moisture in the tire than using conventional air during the Michigan winters. For those that understand dew points, you'd know what I am talking about.

Duke2.6 · #9 07-20-2007, 12:07 PM

Exactly! In fact I've done just that. On exceptionally dry days near the ocean in Southern California when the dew point drops to 10F or less. I've changed the air in my tires to ensure that it is as dry as possible so condensation will never be an issue.

Someone earlier made the following statement:

"Water vapor is not an "ideal gas" and-in the context of race tires- expands in an unpredictable manner."

You need to review a basic chemstry text. Like any other gas at normal temperatures and pressures, water vapor behaves to within one percent of Boyle's Law - same as nitrogen and oxygen. If you want more exacting approximations, review the Van der Waal equations for each gas.

The problem with high humidity in tire air is that if the tire temperature drops to below the dew point, water vapor condenses to liquid and the pressure drops. If the temperature is 80 and the dew point is 60 and the tire temperature drops below 60, like sitting out overnight, water vapor will condense and tire pressure drops.

Of course, when the tire heats up again, either from the heat of the day or operation, it will evaporate again.

Nitrogen - at the cost tire shops charge - is a ripoff, but astute automotive owners should take reasonable care to ensure that tire air is as dry as possible. Most shops have driers, but you never know. If you have your own compressor, install a decent drier on it, which will catch condensation that may form as the temperature drops going through the regulator. And fill your tank on dry days.

If you just use one of those little tire filling compressors that doesn't have a tank, check and add air as required when the dew point is low.

Claims that nitrogen's leak rate is less due to different molecule size is bunk, especially when you consider that air is 78 percent nitrogen. If a tire looses more than 1-2 psi per month is has a minor leak, but you may be chasing a ghost trying to find it unless the leak rate is higher.

And check tires when they are cold and not in the sun - preferably in the morning when temperatures are coolest and before the car is driven.

Duke

Zeus · #10 07-20-2007, 12:17 PM

Quote:

Originally Posted by forp

Our local Costco uses nitrogen in all new tires. The reason is the moisture content. The moisture in the tires expands and contracts at a higher rate than dry air(atomospheric or from a bottle). If your compressor could remove all of the moisture, you'd get the same effect. The higher the moisture content, the more the tire pressure varies with temp. It is not snake oil but a good way to help maintain constant pressure with changes in temperature.
Dan

Yep. x2. And you also get those neat little green tire valve caps. Look at me, I'm riding on nitrogen!

Chas H · #11 07-19-2007, 11:15 PM

[quote=Matt L;1567952]Race teams use nitrogen for their tires because they also use it for their air tools; they can't run compressors in the pits.
quote]

The dryness of nitrogen is exactly why race teams use it to fill tires. That it runs their pit equipment is secondary. Water vapor is not an "ideal gas" and-in the context of race tires- expands in an unpredictable manner.

waybomb · #12 07-19-2007, 11:19 PM

I can't wait to see his wife drive the car at 180 mph and be concerned with the effects of some amount uncontrollable humidity in her tires. Bet that $40 investment pays off at the finish line............

waybomb · #13 07-19-2007, 11:23 PM

What happens when you heat a gas, even a dry gas?

And then if you were to take the same volume, and add a little moisture, and heated it up to normal passenger tire temperature on a 90 degree day on the highway, how much higher would the pressure go?

Spend the money on a good gage and an alignment.

Puck · #14 07-19-2007, 11:35 PM

LOL!! If my wife can get that Pacifica up to 180, I'll buy you all a McLauren!!!

Actually, after reading these posts, and learning how much nitrogen really costs, I think Chas H hit it right on....$40.00!!!! Oh well, live and learn, huh?

Racekar · #15 07-20-2007, 01:46 PM

You do notice it in a race car. My Mazda starts at 34 psi cold and it rises to about 40-42 depending on outside air and track temp with air. With nitrogen the tires don't increase as much in pressure. At 32 psi my car slides around and is a handfull untill the pressure comes up in a few laps. With nitrogen I can start at 36 and it still rises to 42, but starting at 36 makes for a more controled first few laps.

For a street car it makes no difference, even if you do track days you can do a few laps to warm up the tires before realy getting on it.