For you mechanics

[DogRescuer]

Get this my sister in law took her 2016 Rogue to a reputable tire shop because the indicator showed a low tire . The tire was 2lbs low so before the mechanic put air in the tire he asked " do you want regular air which is free or oxygenated air at $5 @ lb". What the crap, is this correct or a scam, can someone explain?

[LSNAutoDetailing]

He's referring to nitrogen filled tires.
This will prevent the mix of moisture in the regular compressed air from fluctuating the tire pressure... i.e. cold day, warm days, sitting still for long time...
Nitrogen will hold a constant pressure.

See this article:

https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=191

What are the effects of using pure nitrogen to inflate tires?

• Nitrogen is a gas and is still affected by changes in ambient temperature (about one psi for every 10° Fahrenheit). Nitrogen filled tires will require pressure be added during the fall/winter months as ambient temperatures and tire pressures drop. Nitrogen is good but can't change the laws of physics.
• Nitrogen reduces the loss of tire pressure due to permeation through rubber over time by about 1/3. This helps maintain the vehicle's required tire pressures a little longer, but doesn't eliminate the need for monthly tire pressure checks. This is good for people who don't maintain their vehicles well.
• Nitrogen is a dry gas and will not support moisture that could contribute to corrosion of the tire's steel components (bead, sidewall reinforcement and belts) due to the absence of moisture over extended periods of time. However it's important to remember that atmospheric pressure is constantly pushing oxygen and moisture into the rubber from the outside of the tire. This is especially good for low mileage drivers who don't wear out their tires quickly or those that run average annual mileages but use long wearing radial (60K and 80K warranted) tires.
• Nitrogen assures more consistent pressure increases due to increases in operating temperatures in a racing environment because of the absence of moisture. This is especially good for participants in track days, high-performance drivers education schools and road racing.
• Drivers should use standard air if pressure adjustments are required when a local source of nitrogen can't be found during a trip. While this reduces the benefit of higher nitrogen content, it is far better than running the tires underinflated in search of a source. Often the original nitrogen provider will refill the tires for free or a nominal cost when the driver returns to his hometown

[Setec Astronomy]

I think he meant "deoxygenated" air. It's ridiculous, I understand using nitrogen in tires, but there are a lot better ways to get it than the machines they have at these tire dealers. My tire guy said to me...if the oxygen leaks out faster than the nitrogen (the major components of air), then eventually you will have all nitrogen in there anyway, even if you are filling with air.

Someone on this forum linked me a discussion about it...and it turns out the moisture content of the air is a lot more important to the maintenance of pressure than the oxygen content.

[LSNAutoDetailing]

I was going use nitrogen because in the North East, I was so tired of my tire pressure changing. Believe it or not, it was hard finding a tire place that actually uses it... probably $$$$. So instead, I opted to use hydrogen... I just have to avoid pot-holes.

[Cruzscarwash]

5$ is really cheap, and if I remember correctly you need to remove all the air from the tire, dismount them and wipe the inside clean to remove any moisture. then you fill it back up with nitrogen. I had nitrogen at a place I used to work at in SC so made the switch and it was pretty nice. ive always been one to track my MPG and I did have a 2mpg increase, while that does not seem like a lot for me it was amazing, I was an ECOmodder at the time and my goal was to get 100mpg but best I ever got was 50MPG.

[oneheadlite]

I guess I'll chime in from the other end of the spectrum (and as a technician for 17 years). I worked at an Audi dealership which switched to "nitrogen". They had a machine you hooked to all 4 tires, which it then deflated and filled with nitrogen (converted from atmosphere - no tank that got refilled) 3x. Never noticed any difference on the cars that had had it done.

Working at an independent shop now, I will say every car I see with green valve stems (to indicate a nitrogen fill) is usually 5-10+lbs low on air pressure. Because with nitrogen it never goes down!

I'm no science whiz, but aren't nitrogen molecules smaller than oxygen anyway, thus fitting through smaller spaces? (IE: Bead leaks, etc).

IMHO, save your money!

Also - the TPMS light going off due to a 2lb drop - that's a pretty sensitive system! The cars I work with usually need a shift of around 7-10.

[VISITOR]

Happy Birthday DogRescuer!

[DogRescuer]

Thanks to all of you very much. Never stop learning.

[Setec Astronomy]

I'm no science whiz, but aren't nitrogen molecules smaller than oxygen anyway, thus fitting through smaller spaces? (IE: Bead leaks, etc).

That's what I thought, too, or at least that they were about the same. But everybody tells us different.

I think those machines are all for show--as you noted, if you look at the specs, since they are using a membrane technology to separate the oxygen from the air, and it's not that good, IIRC the output was 95% nitrogen, and 5% oxygen/other. It's an awful expensive way to do it, seems to me.

[Ceerokz]

If you live where temp change a lot nitro is good. A lot of aircrafts use nitro.