Nitrogen in tires

[ZEEEE06]

When I had my rims changed, the dealer pumped up the tires with nitrogen at no extra charge. I realize the air we breath is 79% nitrogen. The one benefit I've seen is that the tire pressures are holding more consistent than they were before. Any other opinions on nitrogen in the tires?

[86DSOMVERT]

I had Nitrogen put in my Triple Treds on the Impala. Don't notice much difference. MPG is about the same

[Nytro]

Fundamentally, air, oxygen and nitrogen will all behave exactly the same, in terms of just how much pressure will change for each 10 degrees of temperature change. However, temperature alone is not the whole story. Ambient air contains moisture, which nitrogen does not. If moisture is there, it contributes to a greater change in pressure, simply because at lower temp, water condenses to become a liquid. A liquid form of water occupies very little volume and contributes only a negligible pressure to the tire. But at higher temp, water becomes a gas; water evaporates inside the tire as temperature rises. With ambient air, which contains about 20.9% oxygen, the oxygen permeates through the rubber of the tire, so some leaks out. With nitrogen, containing only a little residual oxygen, pressure changes due to oxygen loss are greatly reduced. So, on both counts, the race car guys are correct; nitrogen is more predictable - nitrogen is dry; it has no moisture to contribute extra pressure changes with temperature. And nitrogen permeates out much slower than oxygen, so pressure changes due to that leakage are almost eliminated, compared with ambient air.

[CREWZIN]

Right after I put on my new Z06 replica wheels and Goodrich Sport tires I saw an ad from my local Chevy dealer about Nitrogen. Thought...what the heck and had them filled with the stuff. Along with the fill came a year road hazzard on the tires plus towing and a check of the pressure forever. Check the pressure on all my cars anyway and have noticed that the Vette is staying pretty constant while I just had to add about 3-4 lbs. per tire to my daily driver since the weather dropped into the lower 40's the last couple of weeks. Other than that, I don't notice any difference.

[ynkedad]

Was that off the top of your head or what?

To kind of go along with the Original question... If you lose some pressure in a tire, can you put the "air stuff" in on top of the Nitrogen?

Thanks,

~Ray

[Nytro]

Originally Posted by ynkedad

Was that off the top of your head or what?

To kind of go along with the Original question... If you lose some pressure in a tire, can you put the "air stuff" in on top of the Nitrogen?

Thanks,

~Ray

I read that some time ago from Nascar, they use nitrogen in all their racing tires. To answer your question about topping off, Topping off nitrogen-filled tires with “plain old air” is no problem. It is recommended that you use nitrogen in your tires whenever possible, but if you run into a situation where you can’t get it, no problem. Go ahead and “top off” your tires with air. Later, you can go back to the tire dealer who inflated your tires with nitrogen for a refill.

Also, nitrogen as an inflation gas has no affect on the TPMS sensors. The sensors relay compressed air and nitrogen the same. The Tire Pressure Low light should not be on if your tires are properly inflated with nitrogen to the manufacturer’s recommended pressure.

According to leading tire experts, it’s OK to use more than 93-95 percent nitrogen in your tires, but that’s all you need to gain all the benefits of using nitrogen.

There is no conversion factor necessary for filling tires with nitrogen vs. air. Simply inflate tires with nitrogen to the manufacturer’s recommended PSI rating.

[Mark Dalton]

Years ago in the Air Force, I worked on the SR-71. The tires on that aircraft were filled with nitrogen for the very reason Nytro mentioned. Of course, it was exposed to much higher temps than your car, but the same thing applies.

[2Vettes]

Great info Nytro, thanks

[ynkedad]

Nytro!
for the information man!

~Ray

[9T8Vette]

Awesome read Nytro