Nitrogen in tires
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kizashigal
- Posts: 116
- Joined: Sat Jul 30, 2011 4:48 am
- Location: Colorado
My car came with nitrogen in the tires. Anyone noticed a difference?
2011 Kizzy SE AWD Deep Sea Blue
*drive it like you stole it*
*drive it like you stole it*
Something I posted on another forum awhile back.
I have seen people asking if it is better to put nitrogen in their tires... Here is one of the better answers I have found regarding the question. The only thing he seems to miss is that there is a study that suggest nitrogen-filled tires will remain properly inflated three times longer than "air-puffed" companions.
To answer your question directly. You are unlikely to notice any difference it the Kizashi. If it came with nitrogen that is good, but don't spend any extra money to fill it back up with nitrogen if you get a flat.
I have seen people asking if it is better to put nitrogen in their tires... Here is one of the better answers I have found regarding the question. The only thing he seems to miss is that there is a study that suggest nitrogen-filled tires will remain properly inflated three times longer than "air-puffed" companions.
Personally I think air is the best way to go(it is a good time to check your tread), but like it says above moisture is probably the most important factor so some dingy gas station with free air might not be providing the driest compressed air on the planet.Cecil Adams wrote:Oh, there are plenty of benefits: (1) Cool fluorescent green valve stem caps (assuming your nitrogen vendor has any marketing savvy), which will look sharp with your spinning wheel covers. (2) Bragging rights. OK, you were behind the curve with cell phones, iPods, thong underwear, etc. Nitrogen in tires is relatively new to the mass market. Now's your chance. (3) Reduced fire danger next time you land your space shuttle or commercial aircraft, and tell me you won't sleep better knowing that.
Most tires are filled with compressed air, which when dry consists of about 78 percent nitrogen, 21 percent oxygen, and 1 percent other gases by volume. Water vapor (humidity) can make up as much as 5 percent of the volume of air under worst-case conditions. Filling your tires with nitrogen mainly does two things: it eliminates moisture, and it replaces skinny oxygen molecules with fat nitrogen molecules, reducing the rate at which compressed gas diffuses through porous tire walls. That means, theoretically at least, that a tire filled with nitrogen retains optimal pressure longer, leading to more uniform tire wear and better gas mileage. The commonly quoted figure is that tires inflated to 32 psi get 3 percent better mileage than at 24 psi.
Does nitrogen make any practical difference? You couldn't prove it by me. I found no scientific tests showing that nitrogen-filled tires stayed inflated longer than average under normal conditions. A car-buff buddy was sure it worked but conceded he had only anecdotal evidence that it did.
As for moisture, changes in humidity affect tire performance two ways. First, the density of humid air fluctuates more with temperature than that of dry air, so removing humidity can keep your tire pressure more consistent, especially when the temperature climbs over 100 degrees Fahrenheit. That may be a legitimate concern in Formula One racing, but it's not much of an issue if you're just tooling around town.
Humidity can also be a factor in wheel maintenance - since pure nitrogen doesn't have moisture in it, supposedly your wheels won't rust as quickly, which could lead to improved wheel performance and air sealing. The question is, how big a problem is wheel rust these days? According to a few tire and wheel shops we contacted, not very. Seriously rusted wheels are uncommon in typical steel-wheeled cars, and many high-performance cars have alloy wheels that don't rust at all. One exception is work vehicles such as dump trucks, which are exposed to a much harsher environment.
Another claim I've seen is that since nitrogen is slightly lighter than air, you'll save weight and get better performance. However, we're talking about a weight difference of less than 4 percent of the gas in the tire - in other words, a difference of less than an ounce for most vehicles. A possibly more realistic benefit is that nitrogen is largely inert chemically at low (i.e., normal) temperatures, so it won't attack the rubber in your tires like oxygen does. Oxygen attack is something both the National Highway Traffic Safety Administration and Ford Research have studied, and can be a problem for tires used for a long time or in rough conditions.
More important, nitrogen doesn't support combustion, which is one reason aircraft and the space shuttle use nitrogen in their tires. The wisdom of this precaution was brought home by the crash of Mexicana Airlines flight 940 on March 31, 1986. Shortly after the Boeing 727 took off from Mexico City en route to Puerto Vallarta, an overheated landing-gear brake caused a tire improperly filled with air instead of nitrogen to overheat as well and explode, rupturing fuel and hydraulic lines. The ensuing fire and crash killed 167 passengers and crew. However, unless your driving habits are of the X-treme variety, the chances of your tires catching fire anytime soon are slim.
Overall, filling up with nitrogen won't hurt and may provide some minimal benefit. Is it worth it? If you go to some place like Costco that does it for free with new tires, sure, why not? Elsewhere, though, I've seen prices quoted as high as $10 per tire, which is way more than I'd pay. Rather than shell out for nitrogen, you'd be better off just checking and adjusting your tire pressure regularly, something the NHTSA says less than 60 percent of U.S. motorists actually do.
To answer your question directly. You are unlikely to notice any difference it the Kizashi. If it came with nitrogen that is good, but don't spend any extra money to fill it back up with nitrogen if you get a flat.
I don't remember anywhere in the Ideal Gas Law for what gas it is. PV = nRT - pressure and expansion are the same, only determined by temperature regardless of the kind of gas in the tire.
The moisture content may play a role, but as mentioned above, it's pretty minimal. If anything, I think this is the key, is that it is dry - and that really comes from the production process, not as a nature of being nitrogen. The moisture is removed as part of the "distillation" process of removing the oxygen and other elements of air to leave nitrogen.
As for oxygen attack of the rubber, you're still getting it from the outside, if not the inside of the tire, so I don't see how that can matter.
If you're making the argument about the size of the molecules and leakage, you must be a bit more demanding of constant pressure than would be reasonable.
The moisture content may play a role, but as mentioned above, it's pretty minimal. If anything, I think this is the key, is that it is dry - and that really comes from the production process, not as a nature of being nitrogen. The moisture is removed as part of the "distillation" process of removing the oxygen and other elements of air to leave nitrogen.
As for oxygen attack of the rubber, you're still getting it from the outside, if not the inside of the tire, so I don't see how that can matter.
If you're making the argument about the size of the molecules and leakage, you must be a bit more demanding of constant pressure than would be reasonable.
2011 Sport SLS with nav Black Pearl Metallic
Unfortunately, it's a bit more complex than this...
Moisture causes cooling and lowers gas density, the inversion temperatures for Oxygen and Nitrogen are significantly different, air contains moisture, the compressability of air is different than Nitrogen, and a tire is constantly changing shape and in motion, so the rules change...
I think Nitrogen is less erratic...just call it a hunch...
Moisture causes cooling and lowers gas density, the inversion temperatures for Oxygen and Nitrogen are significantly different, air contains moisture, the compressability of air is different than Nitrogen, and a tire is constantly changing shape and in motion, so the rules change...
I think Nitrogen is less erratic...just call it a hunch...
We don't need to into the debate about what "compressibility" means, and how it doesn't apply here.
I think the point is that nobody would argue that nitrogen is better than air, but I also don't think many would argue that you would need to be in extreme circumstances (f1, aircraft) for that slight difference to matter.
On my trucks, we regularly fill the tires with CO2 - arguably much worse than air - more of a difference than nitrogen to air for sure - and hardly notice the effects that nitrogen is claimed to improve.
If it's free (like at Costco) go for it. It's certainly not something you want to pay extra for
I think the point is that nobody would argue that nitrogen is better than air, but I also don't think many would argue that you would need to be in extreme circumstances (f1, aircraft) for that slight difference to matter.
On my trucks, we regularly fill the tires with CO2 - arguably much worse than air - more of a difference than nitrogen to air for sure - and hardly notice the effects that nitrogen is claimed to improve.
If it's free (like at Costco) go for it. It's certainly not something you want to pay extra for
2011 Sport SLS with nav Black Pearl Metallic
You are the one trying to correct me LOL, Nitrogen is less erratic, ha, take that, I said it again~tc~ wrote:We don't need to into the debate about what "compressibility" means, and how it doesn't apply here.
To be honest, I think along the same lines as you, but I do think that Nitrogen makes a difference in cold weather when tires are transitioning from frozen to hot...