Why Are Tires Filled With Nitrogen?
- Nitrogen is a dry gas, so it won’t corrode the steel in your wheel and tire.
- Nitrogen also inflates the tire at a slower rate than air, which helps reduce the chances of damage to wheels and tires.
- Since nitrogen molecules are bigger than oxygen molecules, they don’t seep out of your tires as quickly as air does. This means you can go longer between fill-ups without sacrificing vehicle performance.
- Using nitrogen in your car tires not only keeps them inflated longer, but also maintains a more stable pressure inside the tire.
Nitrogen keeps your tires at the correct pressure
The primary benefit of nitrogen is its ability to keep a tire inflated at the correct pressure longer than air. Air contains oxygen, whose molecules are smaller than those of nitrogen. It is therefore easier for oxygen in the air to escape through a tire’s rubber material than it is for nitrogen molecules.
Nitrogen also does not expand and contract with temperature changes like compressed air does. That means that nitrogen-filled tires maintain consistent pressure regardless of whether it’s hot or cold outside or even if you drive from one climate into another.
One of the biggest problems with tires is checking the pressure
A lot of people think they should be checking the air pressure in their tires once a week, but you actually only need to do it once a month. I know that sounds like a long time, but there isn’t much point in checking them more often than that. The only time you should check your tires more frequently is when you’re headed on an extended road trip—you do not want to risk getting a flat tire when you’re alone in the middle of nowhere.
But even if you’re due for a tire check-up, it’s not as simple as just looking at your tires to see if they look low (contrary to popular belief). And even if it looks like your tires are low, how much air should go back into them? What can happen if there’s too much air? It turns out that overfilling your tires is just as bad (or worse) than under-inflating them. This is why having a tire gauge is so important: it allows you to measure how many PSI (pounds per square inch) of air are already inside each tire so that you don’t accidentally overfill them or leave them half empty and risk getting into an accident.1
The other benefit of checking your PSI regularly is that it makes sure the ride feels good in all kinds of weather conditions. You wouldn’t want to get caught during rain season with lower pressures than usual because the car will feel very squishy and unsafe—plus water has nowhere to go except underneath the car which can lead to hydroplaning and loss of control!
Why don’t you just use air that’s free?
No, you’re not wrong. Nitrogen is actually the major component of air, making up 78% of the gas. In fact, “air” is a mixture of nitrogen and oxygen primarily, with smaller amounts of other gases like argon, carbon dioxide and water vapor. So why bother paying to replace your car’s air with nitrogen?
One word: consistency. While nitrogen is abundant in our atmosphere, other molecules are present that can cause problems for tires and their internal rubber components over time (think: oxidation). The issue is that these issues tend to happen gradually as the tire ages so you likely won’t notice them until it becomes a problem, or until it’s too late to prevent one altogether.
Maintaining consistent pressure in your tires will help prevent them from wearing unevenly (that leads to increased gas mileage!), and since nitrogen doesn’t leak through tire walls as readily as compressed air does—and because it’s less susceptible to temperature change—nitrogen-filled tires will maintain more constant pressure overall.
Tires filled with nitrogen stay at the right pressure longer
Tires filled with nitrogen may last longer and provide better handling than tires filled with regular air. There seems to be an increasing number of tire stores that fill your tires with nitrogen, but what is the deal? What difference does it make? How is nitrogen different from the air we already have in our tires?
Air is 78 percent nitrogen, so filling up your tires with pure nitrogen isn’t going to make a huge difference (unless you’re filling your tires with pure oxygen). However, it’s not just about what you’re putting in your tire—it’s also about what you’re leaving out. Nitrogen has a few advantages over regular old compressed air. First off, it doesn’t leak out as quickly. Nitrogen molecules are larger than oxygen molecules and pass through rubber more slowly.
Nitrogen also won’t expand or contract as much in the heat. Cars run their hottest when they’re fully loaded—taking a summer road trip on hot highways can really heat up the rubber in your wheels. In the winter, driving on snow and ice will cool down that same rubber until it’s brittle and dry