Nitrogen vs. Air in your tires

[richardcoxid]

Moderator: I am not sure where this post should be, if you want to move it to a better category its OK by me.



Below is what I saw in the automotive section of recent issue of a Salt Lake City, UT newspaper.



“Get Nitrocized for free at XXXXXX” (with purchase of a car from XXXXXX)



“Nitrocize Package- We replace the air in your tires with nitrogen!”

• “increases fuel economy by up to 10%”

• “increases tire life by 30% or more

• “decreases activation of your Tire Pressure Monitoring System”



What does the above advertisement mean?



How can nitrogen increase fuel mileage? (Notice; “up to”)



How can nitrogen increase tire life? (Notice; “increases tire life by 30% or more”)



My 1955 edition of “Machinery’s Handbook” and what little I remember about basic chemistry is that air is composed of; Nitrogen-78%, Oxygen- 21% and Argon- 1%.



I always thought that race cars used Nitrogen in their tires because of the moisture (water vapor) contained in standard compressed air as well as the high temperature they operate at.



Richard

 

[KLauber]

100% nitrogen is inert compared to standard air mixture. If you remove the O2 component there will be less oxidation potential. If the dealer or shop will do a N2 flush n fill for free or nominal charge, it can't hurt. Doubt it will increase your mileage as the rolling resistance and sidewall flex are not going to change much whether you have 35 PSI of air or N2 or Argon. IMHO.

Ken

I did my tires for 10 bucks at the dealer, ok?

 

[rscurtis]

Nitrogen does not leak as readily as oxygen, so if you had a leaky tire, and never checked the pressure, nitrogen might give some improvement in tire life and MPG, but that would be the only scenario where that claim would be valid. It also reduces the pressure change between hot and cold tires.

 

[HBarlow]

I think it would be fair to describe that paid advertising you quoted as hype or exaggeration.

 

[richardcoxid]

HBarlow



I forgot to mention that I thought it was advertising hype.



I would think that the cxidation inside the tire would be a greator problem because you have O2 as well as UV on the exterior of the tire.



Richard

 

[TFucili]

I think it would be fair to describe that paid advertising you quoted as hype or exaggeration.

Yes, snake oil. It is used in aviation to avert explosion of flammable compounds that may accumulate with compressed air. In automobiles... snake oil.

 

[Drewhenry]

Inert gases

Heck If we are going to be selective lets use Helium. Maybe it will make our rigs lighter and we can get economy car mileage



AB

 

[JMetzger]

I run Nitrogen in the RV tires & I do know that since I have been using Nitrogen I have not had any tire issues & the tires run cooler. As for mpg gain I don't know. Have Nitrogen in car tires & didn't see any mileage gain, just cooler running which is better for the tire.

 

[Wingate]

Heck If we are going to be selective lets use Helium. Maybe it will make our rigs lighter and we can get economy car mileage



AB

HAHAHA... I like your logic!!. . I've often wondered if a fully loaded 18 wheeler hauling helium weighs more or less than the same truck with empty tanks????. .

Personally, i think the nitrogen thing is b/s for on highway cars... Local dirt track racers use it because it doesnt build as much pressure when the tire heats up. Of course, those are totally different conditions vs. driving down the highway. . If O2 isnt good enough, then maybe we need better tires???

 

[p-Bar]

The idea is that the O2 molecule is smaller than the nitrogen molecule so it won't leak through the rubber. I heard Costco does it

 

[PBJ2500CTD]

I run Nitrogen in the RV tires & I do know that since I have been using Nitrogen I have not had any tire issues & the tires run cooler. As for mpg gain I don't know. Have Nitrogen in car tires & didn't see any mileage gain, just cooler running which is better for the tire.

There is a lot of truth to nitrogen maintaining stable tire pressures and cooler running tires. In the 80's a number of heavy aircraft were experiencing catastrophic tire failure on takeoff after an extended taxi on a hot day, especially at a different altitude than the tire was last serviced. By inflating with nitrogen the heat/altitude related tire failures on takeoff were almost entirely eliminated. Nitrogen, being a larger molecule than oxygen, will not as readily permeate the tire's inner lining like oxygen will. This helps keep the tire's carcass together since any gas, be it oxygen or nitrogen, that permeates the liner can cause ply or tread separation.

F1 race cars also use nitrogen in their tires.

An excerpt from Wikipedia:

... The main purpose of requiring that an inert gas, such as nitrogen, be used instead of air, for inflation of tires on certain transport category airplanes is prompted by at least three cases in which the oxygen in air-filled tires combined with volatile gases given off by a severely overheated tire and exploded upon reaching autoignition temperature. The use of an inert gas for tire inflation will eliminate the possibility of a tire explosion...

... and... a website or two containing good info...

Olson Bros. * --* Nitrogen Filled Tires

Nitrogen VS. Air Inflation... Which is better you ask?? - Automotive Discussion Topics - MySears Community

 

[mhenon]

I agree with all that but for the average guy on the street there's going to be little difference. Costco does fill there tires with nitrogen BTW. The last set of Michelin's I bought there came loaded with nitrogen and pretty green valve caps. Mileage actually went down a bit (new tires are a little sticky ya know!!).

Bottom line... . you won't save any fuel using nitrogen.

Mike

 

[Road Dog]

An excerpt from Wikipedia:



... The main purpose of requiring that an inert gas, such as nitrogen, be used instead of air, for inflation of tires on certain transport category airplanes is prompted by at least three cases in which the oxygen in air-filled tires combined with volatile gases given off by a severely overheated tire and exploded upon reaching autoignition temperature. The use of an inert gas for tire inflation will eliminate the possibility of a tire explosion...

Two reasons to be skeptical of Wikipedia. N2 (nitrogen molecule) isn't inert. It reacts with oxygen to form NOx and is the reason Diesel engines give up efficiency for emissions. Second, I saw a Mythbusters recently where they tried to set a tire on fire with a burnout. The result was BUSTED -- the tire will always come apart before it reaches the burning point.

 

[PBJ2500CTD]

Two reasons to be skeptical of Wikipedia. N2 (nitrogen molecule) isn't inert. It reacts with oxygen to form NOx and is the reason Diesel engines give up efficiency for emissions. Second, I saw a Mythbusters recently where they tried to set a tire on fire with a burnout. The result was BUSTED -- the tire will always come apart before it reaches the burning point.

Ah, Mr. Road Dog. I must respectfully disagree with both you and MythBusters on the two points brought forth.

1. Tires WILL burn very nicely without flying apart in millions of pieces - well, at least without large chunks flying anyway... they may melt and spatter millions of globs of very hot (and painful) bits of rubber and leave one heck of a mess as they produce a very nice pyro show. It will depend upon the compounds the tires are made from. I can attest to this from firsthand experience in 1968/69 on a 65 Mustang 289 Hi-Po with G60 Atlas tires - sold at Standard Oil and ESSO stations.

2. NOx forms at much higher temperatures than will be found in operating tires - unless the tires are burning with the assistance of a magnesium rim. (Gads, that's HOT!) The NOx is produced during the engine's combustion cycle where temps reach 1200* to 1800*+F. Tires do not get anywhere near those temperatures. And dry nitrogen is not flammable. It is almost inert. It's those silly little oxygen atoms that cause so much fun, or damage.

3. Yes... from an after-the-fact observation stored on a way back memory cell, the rear axle WILL be severed from a car with LEAF springs, given sufficient length of sturdy logging chain, a well established tree, and enough momentum from the... uh, pursuer. MythBusters used a contemporary car with a very sturdy coil spring setup (a herky Vicky) with a hefty 4 link connection, that had an equally hefty stab link. Try it with 4 wimpy shackle mounts and some U-bolts, and see what happens. The unfortunate pursuer was admitted to the hospital with some major internal and neck injuries. (Pre-seat belt era) The car was tweaked pretty good, too. [SIZE=+0] OK... This wasn't one of your points, but MythBusters has occasionally admitted that some of their busts could be defective; and this, in my life experience book, qualifies as a busted bust, as does the tire flambe. [/SIZE]
[SIZE=+0][/SIZE]
I am generally skeptical with anything Wiki has to say. However, part of the cited article was derived from an FAA article and other parts from very reliable sources (moreso than the usual Wiki input).

 

[Road Dog]

Going back to earlier articles, N2 is referred to as mostly inert. I guess to save some typing "mostly inert" became "inert". And I'm sure some student will include "nitrogen is an inert gas" in a science paper and some science teacher -- who doesn't need to know any science to teach it -- will accept that it's true.

Good point about Mythbusters. I'm sure they used modern radial tires for their test and never considered other tires and their composition.

 

[rbattelle]

Before installing the nitrogen, do they pull a full vacuum on the tire to remove all the air? If not, then you're not running 100% nitrogen.



We've talked about this sort of thing before. Here are a couple threads:

Thread 1.



Thread 2.



Ryan

 

[BullyDogJason]

I can see the claims that you wont leak air as much. but the rest i dont buy

 

[CharlesHoward]

My Father's seldom driven Nissan hasn't needed any Tire refilling in almost 2 years since Nitrogen was put in his tires. I check them about every 6 months - no change!
I would try it in my Ram Tires, but I sometimes air them up or down for load and comfort changes...

 

[BIGNASTY]

Costco

I know that Costco filled with Nitrogen but after using the TT at least a couple of time's a Mo. I adjust tire press. before use and after use. So how much Nitrogen is left in the tire. Im not going to Costco to have adjustments all the time.

 

[JMetzger]

When I worked in the AC business we used a lot of Nitrogen so I had a large cylinder left over so I use it for the RV & car. The truck just has plain old air.