Somebody educate me on "Nitrogen" in the tires ?

Inflating tires with N2 has a few real and some theoretical advantages. However many of the sales claims are based on the assumption that the vehicle owner never monitors or maintains tire inflation.

The issue come up when facts are considered. Tires inflated with "AIR" have about 78% N2. Under test conditions 3 years later due to normal out-gassing of the O2 and addition of more air a tire will end up with about 82 to 85% N2.

Most shops offering N2 are not using pure bottled N2 but are using a nitrogen separator so are creating a gas that is about 98 - 99% N2. When you inflate a tire with 99% you do not end up with 99 as there is O2 left in the tire originally and even a 3x fill and purge does not remove all the O2 so you end up with about 94-96% N2.

Cost If there was no cost I would say do it but there is a cost both direct payment to dealer and sometimes additional travel time & cost to dealer location.

pay-back Doubtful as MPG is theoretical and probably may not even measurable if all performance characteristics are considered. Tire life may also be doubtful since most RV tires are replaced due to age.

Did some administrative research on this and next document came from it.

Filling car tires with normal air is better then with Nitrogen.
A. Oxygen, which makes 21% of normal outside air, in volume absorbs more energy to rise a degree in temperature then Nitrogen.
Difference is only 1% , but in selling argument is sometimes mentioned in energy/ mass so Joule/kg.degr. Kelvin and there Nitrogen wins by 13 % . Tires though are filled with a certain volume so that counts .
This selling argument can be de-myth simply by the fact that its untrue.

B. Water in a tire transports the heat more then dry air or Nitrogen-filling ( which is by its production process free of water).
Not for no reason water is used in central heating and cooling system of cars as main substance.
The tire inside will have lower temperature which is better for cooling down the important spots of the tire wich have to keep a low enough temperature to prevent hardening and damage in next bending of those parts.
When incidentally the tire inside gets hotter ( sunshine on tire or severe braking, or high ambient temperature) more water goes over to gas wich highens the pressure inside the tire more then dry gas. Also then more water as gas in tire so even better cooling.
So advantage of water is 2 ways when needed, better cooling and lesser heat production.
Disadvantages of water as oxidation only happen at outside . Tire specialists will confirm that when they remove a tire of the rim , the rim inside the tire is not corroded.

C. When a Truck, transporting flammable substance, is on fire, the little oxygen in a tire will , when exploding ,probably even kill the fire .
In tunnels experiments where done to kill the fire with air current , and it worked, despite the oxygen in it.

D. A normal car tire up to truck tire is not a race-car tire, for which a constant as high as possible contact area, so best grip , is needed to give half a second better round time.
For that reason they are filled with as dry as possible air or Nitrogen.
That this gives low lifetime is not important, and for a normal car tire it is.
Often blowing tires at racing, is seen there as collateral damage, but we don’t want that for normal car tires.

E. A car tire is also not a airplane- tire in which the water can freeze and when landing this can give misbalance , which can lead to tire-failure or accident, when suddenly going from zero to about 200m/h.
The water in a car tire does not freeze that often, and when it does and the car begins do drive , it begins slow and the misbalance is not a big problem . then pretty soon, certainly when on speed the ice is melted to water and problem will be gone.

F. When filled with normal air the user is aware of checking the tires regularly, which takes better care of a saver tire, because regularly filled up to the right pressure and optical checking of the tire .
The illusion that Nitrogen filling makes the tire to loose almost no pressure, which is often exaggerated to 5 times , while in real a poor 2 times and then only in the very beginning, makes the user less caring .
The tire also looses air when hitting pavement so temporary leak between edge of tire and rim, Filling with whatever gas-combination won’t prevent that.
This idea is even stronger when TMPS is used which is often inaccurate , so the user thinks to maintain the right pressure, while really riding with to low pressure for longer time, which can lead to tire damage. Aftermarket sensors for TMPS when screwed on the valve can give leakage trough hole where valve is placed , because of the bending of the valve by centrifugal forces at speed.

G. Filling with normal air is always possible, even with a bicycle- pump, is only to fill up so won’t take that long. When you keep driving with to low pressure , in order to find a place to fill with Nitrogen, you damage your tires. So just fill up with normal outside air, even when the tire is filled with Nitrogen. Then also you don’t need to have the tire refilled with pure Nitrogen by your tire specialist when at home again, not worth the trouble, and normal air is even better then nitrogen because of the water in it.

Bottom line: There is no downside but cost. Don't spend money to get it, but if you got it, don't change anything else about how you care for 'em. Still gotta check pressure and add plain air if low.

So , now I am educated and wondering why they spent the extra bucks to put Nitrogen in the tires but spent so much less on quality workmanship on the interior of the trailer ?

Thanks every one for the various replies

Jack L

mike-s wrote:

Turtle n Peeps wrote:

rbtglove wrote:
Nitrogen is used in A/C tires and some race cars primarily because it is not flammable like the oxygen in air.

Oxygen is flammable?

In a literal, pedantic sense, no. But the GP's statement should be taken to mean that nitrogen doesn't support combustion like oxygen does.

If my tires or race car is on fire, the last thing I'm going to worry about is the 20% of O2 in the tires because there is a whole bunch of it around the car to support combustion

Put helium in your tires. Your rig will seem to float down the highway.

safeman wrote:
I keep a precise mixture of 78 percent nitrogen in all my tires:B

LOL! Me too.

rbtglove wrote:
Nitrogen is used in A/C tires and some race cars primarily because it is not flammable like the oxygen in air. It also has a slight advantage in stability/leakage expansion. It is pretty much a waste of money to use in RVs.

BTW, oxygen isn't flammable.

Turtle n Peeps wrote:

rbtglove wrote:
Nitrogen is used in A/C tires and some race cars primarily because it is not flammable like the oxygen in air.

Oxygen is flammable?

In a literal, pedantic sense, no. But the GP's statement should be taken to mean that nitrogen doesn't support combustion like oxygen does.

rbtglove wrote:
Nitrogen is used in A/C tires and some race cars primarily because it is not flammable like the oxygen in air.

Oxygen is flammable? :h