Nitrogen

[jakkay968911]

Anyone know of the pro's and con's about nitrogen filled tires. I decided to go with the nitro option last tire change for the winter. Seems they hold pressure better when the temperature changes occur here in Chicago. Just curious.

[therock88]

My honest opinion are the pros and subjective and assumed at best. The cons are just the cost. Doesn't hurt anything though. Here are some good facts I have collected:

Most tires are filled with compressed air, which when dry consists of about 78 percent nitrogen, 21 percent oxygen, and 1 percent other gases by volume. Water vapor (humidity) can make up as much as 5 percent of the volume of air under worst-case conditions. Filling your tires with nitrogen mainly does two things: it eliminates moisture, and it replaces skinny oxygen molecules with fat nitrogen molecules, reducing the rate at which compressed gas diffuses through porous tire walls. That means, theoretically at least, that a tire filled with nitrogen retains optimal pressure longer, leading to more uniform tire wear and better gas mileage. The commonly quoted figure is that tires inflated to 32 psi get 3 percent better mileage than at 24 psi.

Another claim I've seen is that since nitrogen is slightly lighter than air, you'll save weight and get better performance. However, we're talking about a weight difference of less than 4 percent of the gas in the tire - in other words, a difference of less than an ounce for most vehicles. A possibly more realistic benefit is that nitrogen is largely inert chemically at low (i.e., normal) temperatures, so it won't attack the rubber in your tires like oxygen does. Oxygen attack is something both the National Highway Traffic Safety Administration and Ford Research have studied, and can be a problem for tires used for a long time or in rough conditions. If the weight (1 oz) is an issue, try replacing the Porsche battery with a non OEM. :) Those Moll stock batteries must weight 80 lbs. , and the aftermarket ones with more CCA etc seem to weigh 1/2 as much.

Just some info. Ultimately nitrogen is less flammable (if you are worried about your tires bursting into flames), and I think around $5-10 per tire for the fill....So if it feels better to you fill them up!

Hope this is helpful...and I am sure there are experts out there that know more than me.

DC

Edited February 12, 2010 by therock88

[goldenwarrior1]

Nitrogen is an inert gas and therefore is inflammable. The weight difference between compressed air and nitrogen at normal atmospheric pressures is negligible for the purpose of this case.

[White987S]

I live in Chicago too.

Been using nitrogen for about 4 years. Works great during winter hibernation.

[jakkay968911]

Thanks for the info guys. There was no extra charge for the nitro option at mt indy when I ordered tires through him. Seem to be holding pressure better than last winter with air. I hear that aircraft have been using nitro to keep the inflation pressure stable as altitudes change.

[rrspikemarty]

FWIW, Nitrogen is non-flammable. ;)

[RF5BPilot]

I hear that aircraft have been using nitro to keep the inflation pressure stable as altitudes change.

Large, commercial aircraft do use nitrogen, but primarily because the landing forces on their tires heat them suddenly and dramatically -- nitrogen minimizes that effect. They are dealing with extremes that you just don't see in car tires. I own a small airplane. I just use compressed air. No other pilots I know use anything other than compressed air.

Technically, most of the nitrogen claims are true...but exaggerated. If you got a nitrogen fill for free, great. But its practical value is so small, it's not worth paying for unless you do it for entertainment. You can get hours of garage talk about it. Add a couple of beers, even more. So, it's entertainment value is wildly greater than its practical value.

[wvicary]

Marketing scam to get more money out of your pocket. Don't fall for it.

[70Sixter]

One other thing to remember. We breathe air, not oxygen. About 78 per cent of air is already nitrogen.

[cyclocross]

I check my tire pressures every 2 to 3 weeks anyhow looking for small leaks. To me that is more important than nitrogen's lower diffusion rate.

[geoff]

The nitrogen used to fill tires should have a lot less moisture in it than the air that comes out of a regular air compressor for tires. When you need to fill your tire(s) up and a nitrogen top-up isn't convenient, your choices are to wait until you can get more nitrogen (not necessarily good for your tires), or just add compressed air (somewhat negates the supposed nitrogen benefits).

I have an air compressor and check my tires every few weeks, so don't consider nitrogen a practical option for my tires. I did ask the dealer to put nitrogen into my spare tire, since I don't check it very often and want it to work when/if I need it, so no moisture and less gas loss is a plus for the spare.

[Falcon900EX]

We use nitrogen in our aircraft wheels. It's the moisture issue. E

[rpm996]

I get this question a lot from work colleagues that know me as the office 'car guy.' My answer is based on the individual asking.

If the question comes from another car enthusiast type - I say there is no need to give your dealer (where this often comes from) another $45-60. Just keep checking your tire pressure as you normally do.

But if the question comes from a non-enthusiast (particularly the working mother/minivan/soccer league type - yes, blatant sterotyping, I know...), then I ask them when was the last time they checked the air in their tires. Usually the answer is a quizzical look, or even a laugh. For these folks, nitrogen is a cheap insurance policy they should definitely go for.

My performance tire shop uses nitrogen. But I am not fanatical about replacing with nitrogen and I check my pressure just as often.