Having to pull over during a road trip to fill up your car’s tires is a nuisance that no one ever really wants to do. Especially if you have an older pair of tires, air can leak out pretty quickly, causing this inconvenience to become just a normal part of life.
There are many supposed tips and tricks that can help alleviate this problem. One of the more common tricks of the trade is the nitrogen technique, in which you fill your car’s tires with nitrogen gas instead of oxygen.
Does that really work, though? What are the benefits and drawbacks of nitrogen in tires? Is it safe, and should you do it? Let’s answer all of these questions and more.
To understand the drawbacks of nitrogen, it’s important to know what exactly causes tires to lose air in the first place. For one, tires just naturally lose pressure over time. Small amounts of air penetrate the rubber through a process called permeation. This just happens, even if the car is not in use.
Also, damage to the wheel can cause air to be released much more quickly than a brand new tire. Small holes can cause air to naturally expel a lot quicker than an intact tire, primarily when used consistently.
Also, you may notice that your tires are flatter in cold winter months. While many people think that this is actually because air is escaping the tire, it is actually due to a simple scientific principle: the Ideal Gas Law.
It’s a complex equation, but it states that when temperature decreases, so too will the gas pressure. So a tire in cold weather may visually appear flatter than in warmer months, but the mass of air hasn’t changed. There’s just less pressure of each molecule pushing back on the road.
All of these issues are normal, but the claim is that nitrogen in your tire might be able to fix some of these issues.
Nitrogen is a more stable gas than oxygen, and each molecule is slightly larger. The thought is that by filling your tires with nitrogen, air will permeate, or escape, the tire more slowly. It is also believed that in colder weather, the nitrogen gas will maintain more consistent pressure, meaning that you won’t need to refill your tires as often.
While some of this may be true, there are pros and cons to filling your car’s tires with this abundant gas.
If you’re tired of your tires, it might be worth it to try filling them with nitrogen instead of air. There are a few positive benefits associated.
The atoms of nitrogen are slightly bigger than the atoms that compose oxygen, so nitrogen tends to leak through tires a bit more quickly. Generally, oxygen escapes from a tire at a rate that is 1.6 times faster than nitrogen.
This means that, theoretically, you should get 50% more life out of your tires before needing to refill if you use nitrogen instead of oxygen. That can be a major timesaver for long road trips especially, but it can just be super convenient in your everyday life.
The air that you use to fill your tires contains other elements besides just oxygen. In fact, compressed air is made of 78% nitrogen, 20-21% oxygen, and 1-2% water vapor. Yep, the compressed air you use at a gas station is already 78% nitrogen.
But that small amount of water vapor has the capacity to heat up during long drives that cause high friction. That can lead to accelerated wear and tear on your treads. It wouldn’t make that much of a difference. But if we’re talking about the pros of using nitrogen, this is one of them.
Tires filled with nitrogen maintain inflation pressure for longer than compressed air-filled tires in fluctuating temperatures. That’s actually why many airplane tires are filled with nitrogen, as the pressure remains more contained throughout temperature changes at high altitudes.
This means that you might notice a bit less of a difference in colder climates if you use nitrogen in your wheels instead of compressed air. With that said, the temperature changes that a plane experiences are a lot harsher than what your car would see on the ground, so it’s debatable if nitrogen will help in those circumstances.
There are a few pros to filling your tires with nitrogen, but there are honestly probably a few more cons. Let’s take a look at them.
Pretty much every gas station across the country has compressed air machines that you can use to fill your tires. However, nitrogen tanks are really only available at tire shops, dealerships, or super fancy service stations.
So if you ever need to fill your tires in a pinch, you might need to settle for some classic compressed air at your local gas station.
In addition to being fairly scarce, nitrogen fill-ups cost a lot more than compressed air. Most nitrogen fill-ups cost somewhere around $5 or more per tire. In comparison to compressed air, that’s very steep.
Some service stations offer free air, while others can let you use their pumps for as low as 25 cents for all four of your wheels. And even though you won’t need to refill your nitrogen tires as often, it’s hard to justify paying nearly 80 times the price just for 1.6 times the effectiveness.
While nitrogen might extend the amount of time you can go without needing a refill, it’s not an end-all-be-all situation. You’ll still probably need to refill your tires at some point throughout the year in a similar way that you would with air. The only difference is that filling with nitrogen is so much more inconvenient, so you’ll need to go out of your way to get some more.
Because nitrogen can leak out of tires more slowly compared to air, it’s more resistant to temperature changes, and it can decrease the amount of wear and tear on your tire’s treads. But considering that it’s so inconvenient, costly, and still not a foolproof method, we tend to think that using compressed air is just fine.
Sure, you may need to go refill your tires a bit more often. But it is just so much cheaper and easier than finding a location with a nitrogen pump. The only time we may recommend it is for light trucks or semis that might be driving for long periods of time consistently. This might help keep them afloat on the roads for a while longer.
If you’re going to use nitrogen, we highly suggest that you don’t spend more than $5 per tire. If a dealership or mechanic is trying to get you to pump for upwards of $10 to $20, we are begging you not to waste so much money. At that point, you could have filled your tires with compressed air hundreds of times for the same price.
Instead, we suggest you just buy yourself an accurate pressure gauge or monitoring system to check your tire pressure often. If you notice it’s a bit low, just go get a refill so that you can maintain the durability of your treads for as long as possible.
Also, if your tires are balding or you notice that they’re losing air way too quickly, it might be time for a fresh set. But dropping money on a new set of tires can be even more expensive than filling them with nitrogen (believe it or not!), so don’t spend more than you need to.
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