Author Topic: Nitrogen in Tires? (Read 7118 times)

Ben · « **on:** March 05, 2011, 01:00:08 PM »

Any of you use nitrogen in your tires?

I just got new truck tires and my tire guy filled them with nitrogen. No extra charge for it, and free refills. Just wondering if any of you that use it see any noticeable difference over plain old air. The tire guy told me if I let nitrogen out of say, the rear tires for off-road traction or something, to have him drain and refill the tires with pure nitrogen. Also no charge, so I know it's not to make an extra buck.

Just wondering how much of a real benefit it is over air. I put more aggressive tires on the truck (Bridgestone Revo 2s versus the all season tires that it came with) and saw my MPG stayed the same on a long trip I repeatedly take. Don't know if that's the nitrogen or something else, but I would have expected my mileage to drop at least a little. Tire pressure is the same as before.

TechMan · « **Reply #1 on:** March 05, 2011, 01:13:29 PM »

We have a chain of tire stores here in Cincinnati that does N₂. This is their N₂ sales page: http://www.tirediscounters.com/nitrogen.php I have it, but I will put normal air in it. I have noticed that the psi of the tire stays the same longer than air.

MillCreek · « **Reply #2 on:** March 05, 2011, 01:36:36 PM »

I have done this a few times on the SUV and motorcycle. I never noticed any perceptible difference in MPG or how often I had to top off the tire pressure. If it was convenient and free, I might fill up with nitrogen, but I would not pay for it. Nowadays, when I notice a tire getting low, I just grab one of my floor pumps and top off the pressure. It is quicker and easier to do that than drag out the compressor, the inflator or go to a tire shop for the nitrogen.

Monkeyleg · « **Reply #3 on:** March 05, 2011, 02:01:21 PM »

I doubt that you'd really see the benefits of nitrogen unless you're doing serious racing. Nitrogen doesn't expand or contract with variations in temperature as much as the regular air we breathe, in part because air contains various amounts of humidity versus dry nitrogen, and also because of the nature of nitrogen itself, so race teams use it to keep tire pressure more consistent.

The other supposed advantage of nitrogen versus air is that because the nitrogen doesn't have the moisture that regular air does, the insides of the tires aren't affected by moisture and the insides of the wheels don't rust. At least that's what promoters say.

RocketMan · « **Reply #4 on:** March 05, 2011, 02:03:43 PM »

Given that ordinary air is 78% nitrogen, what's the point? There is no practical difference in molecular sizes when compared to leakage avenues, so leak rates between pure nitrogen and ordinary air will be very similar.
In fact, nitrogen has a desiccant action, so what negative effect might that have on tires?

Lee · « **Reply #5 on:** March 05, 2011, 02:10:25 PM »

Quote

In fact, nitrogen has a desiccant action, so what negative effect might that have on tires?

Probably has more effect on wheels than tires. I used to get flat tires on my old truck because rust would build up between the wheel and tire bead. It would be interesting to see a long term study.
My new truck has N and came with the green valve stem caps...which some jackwad promptly stole.

Zardozimo Oprah Bannedalas · « **Reply #6 on:** March 05, 2011, 02:11:13 PM »

The biggest benefit of nitrogen in tires happens when they burst. Since nitrogen doesn't allow for combustion, it reduces your chance of catching on fire in and around that area. More important if you're driving a space shuttle or jet.

Brad Johnson · « **Reply #7 on:** March 05, 2011, 02:35:18 PM »

Quote from: RocketMan on March 05, 2011, 02:03:43 PM

Given that ordinary air is 78% nitrogen, what's the point? There is no practical difference in molecular sizes when compared to leakage avenues, so leak rates between pure nitrogen and ordinary air will be very similar.

Wurd.

The biggest benefit of nitrogen fills is to the seller's profit margins. People are finally catching on, though, as I'm seeing a lot more places using it as a freebie marketing hook rather than charging $10-$20 per tire for a fill like they were a couple years ago.

I about fell over laughing when I heard the response to someone hailing the benefits of nitrogen. The guy he was talking to responded something to the effect of, "You used straight nitrogen? You should try the special 78% nitrogen blend I'm using. I put it in when I got the tires and they're doing great!" The really sad part? Mr 100% Nitrogen started pumping the guy for more info!

Brad

Ben · « **Reply #8 on:** March 05, 2011, 02:42:17 PM »

Quote from: MillCreek on March 05, 2011, 01:36:36 PM

If it was convenient and free, I might fill up with nitrogen, but I would not pay for it.

That's how I'm looking at it. I've been driving for 35 years on air. The place is between the house and work though, so if they want to put the free nitrogen in the tires whenever I come in for my free tire rotations, it's okay by me.

MillCreek · « **Reply #9 on:** March 05, 2011, 02:43:08 PM »

Quote from: Brad Johnson on March 05, 2011, 02:35:18 PM

I about fell over laughing when I heard the response to someone hailing the benefits of nitrogen. The guy he was talking to responded something to the effect of, "You used straight nitrogen? You should try the special 78% nitrogen blend I'm using. I put it in when I got the tires and they're doing great!" The really sad part? Mr 100% Nitrogen started pumping the guy for more info!

Brad

As a former chemist, this just about made me pee my pants laughing.

CNYCacher · « **Reply #10 on:** March 05, 2011, 02:44:44 PM »

Lets imagine that nitrogen is magical and will never leak from your tires.
Let us also pretend that all other atmospheric gases are evil magic and will escape from your tires at a rapid rate.

Step 1: Inflate tires to 45psi using normal air. Nitrogen level: 78%
Step 2: Allow evil gases to escape. Air pressure: 35 psi, Nitrogen level: 100%

220_SWIFT · « **Reply #11 on:** March 05, 2011, 03:29:13 PM »

I put new tires on my wife's Sorento last summer, and they filled them with Nitrogen for free. The only difference I have seen at all was this winter. I did not have to go put air int he tires when the temps dropped really low. That was a first. Every other winter, as soon as it hit sub-zero, I had to ad air. I would never pay any money for it, but I am not going to run right out and deflate/re-inflate either. Also, it isn't an inconvenience either. I go to the same shop for oil changes, and tire rotation so they check the pressure then anyways. Again, they will refill (if you add air) and top off for free.

lee n. field · « **Reply #12 on:** March 05, 2011, 03:42:38 PM »

Quote

Just wondering how much of a real benefit it is over air

Air is mostly nitrogen, anyway.

bedlamite · « **Reply #13 on:** March 05, 2011, 03:46:20 PM »

Race teams use nitrogen because the pressure is more predictable as the tires heat up. For any car you would drive on the road, don't bother.

Jamisjockey · « **Reply #14 on:** March 05, 2011, 04:14:04 PM »

When I got my new tires last year, they did nitrogen free of charge. I use the synthetic oil and go 5,000 between oil changes. I never have to top off my pressure between oil changes. I usually check them every week.
If its free, do it.

Hawkmoon · « **Reply #15 on:** March 05, 2011, 04:24:50 PM »

Quote from: Brad Johnson on March 05, 2011, 02:35:18 PM

Wurd.

The biggest benefit of nitrogen fills is to the seller's profit margins. People are finally catching on, though, as I'm seeing a lot more places using it as a freebie marketing hook rather than charging $10-$20 per tire for a fill like they were a couple years ago.

I about fell over laughing when I heard the response to someone hailing the benefits of nitrogen. The guy he was talking to responded something to the effect of, "You used straight nitrogen? You should try the special 78% nitrogen blend I'm using. I put it in when I got the tires and they're doing great!" The really sad part? Mr 100% Nitrogen started pumping the guy for more info!

Brad

That reminds me of the joke about how Boy Scouts save weight when backpacking. They don't carry water, they carry dehydrated H2O. Saves considerably on weight and volume.

Just add water when needed.

Monkeyleg · « **Reply #16 on:** March 05, 2011, 05:44:12 PM »

Quote

Race teams use nitrogen because the pressure is more predictable as the tires heat up. For any car you would drive on the road, don't bother.

Thanks for the backup, Bedlamite.

I'm not the one who uses it. If you guys question nitrogen's value, go talk to the guys who race cars about it.

bedlamite · « **Reply #17 on:** March 05, 2011, 05:47:25 PM »

Quote from: Monkeyleg on March 05, 2011, 05:44:12 PM

Thanks for the backup, Bedlamite.

I'm not the one who uses it. If you guys question nitrogen's value, go talk to the guys who race cars about it.

I suppose I should read the whole thread before I post instead of just skimming it.

zxcvbob · « **Reply #18 on:** March 05, 2011, 09:54:31 PM »

If you fill the tires with N₂, oxygen will slowly leak *in* and keep the pressure up. Seriously. (I don't think it's worth the extra expense, but hey if the tire guy fills 'em for free...)

Nick1911 · « **Reply #19 on:** March 05, 2011, 10:05:48 PM »

Quote from: zxcvbob on March 05, 2011, 09:54:31 PM

If you fill the tires with N₂, oxygen will slowly leak *in* and keep the pressure up. Seriously. (I don't think it's worth the extra expense, but hey if the tire guy fills 'em for free...)

Hmm... Osmosis trying to restore the equilibrium of a chemical mixture on each side of a semi-permeable barrier? Sounds plausible, but I question if that effect would work against a significant pressure differential. 46.7 PSIA inside the tire vs 14.7 PSIA outside, a pressure ratio of 3.2.

Any of our resident chemists want to chime in?

French G. · « **Reply #20 on:** March 05, 2011, 11:09:27 PM »

I come from a background that I have personally built hundreds of both race car and aircraft tires. Moisture is advantage #1. #2 is in high pressure aircraft tires that may be there for a long time you are not exposing the inner tire to high pressure oxygen bearing air which will try to find something to corrode along with air's moisture, but also oxidize the rubber. Personally we use air in the race car tires, not Nascar, adjustments are in at least 1lb increments and a lot of time bleeder valves are used to account for tire heating.

KD5NRH · « **Reply #21 on:** March 06, 2011, 06:58:37 AM »

Quote from: Zardozimo Oprah Bannedalas on March 05, 2011, 02:11:13 PM

The biggest benefit of nitrogen in tires happens when they burst. Since nitrogen doesn't allow for combustion, it reduces your chance of catching on fire in and around that area. More important if you're driving a space shuttle or jet.

Uh, what?

Unless you're sitting still when you have a blowout, 90+% of the nitrogen is going to be too far behind you to do any good by the time the rim contacts the road.

P5 Guy · « **Reply #22 on:** March 06, 2011, 01:36:18 PM »

Why not use Helium and reduce the unsprung weight and being an inert or Noble gas Helium will not corrode the wheels or react with the rubber of the tire. Argon would work too but it is heavier than Nitrogen.

Nick1911 · « **Reply #23 on:** March 06, 2011, 02:19:40 PM »

Quote from: P5 Guy on March 06, 2011, 01:36:18 PM

Why not use Helium and reduce the unsprung weight and being an inert or Noble gas Helium will not corrode the wheels or react with the rubber of the tire. Argon would work too but it is heavier than Nitrogen.

Helium is much more expensive then N2.

Brad Johnson · « **Reply #24 on:** March 06, 2011, 02:20:42 PM »

Not to mention those pesky cold fusion problems.

Brad

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Author Topic: Nitrogen in Tires? (Read 7118 times)